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All of these reports are great,but....

It has dawned on me that when Dan put this section together that it would be quite informative. Unfortunately, I don't think it is really doing our industry any good because of the lack of readers and the lack of comments. It is almost as if most people (contractors) don't read this because they don't think that a case of CO poisoning will happen to them on their watch. Ignorance is not a good legal defense in the eyes of the court.

Education is key, and anyone who deals with a flame has the exposure necessary for a carbon monoxide situation. I can name the people who will read this and comment on it on one hand, and that is not right, because as I said, ANYONE who deals with FLAME (oil, gas, coal, wood, LP etc) is in the arena of Carbon Monoxide exposure. It is not my intent to belittle people into participating on this forum. It is my intent to teach what I know in hopes of getting more and better participation, and hopefully actual participation in the field.

I am in the process of inspecting candidate boiler rooms of numerous MFD dwellings here in Colorado for possible replacement, and one key component is a review of the combustion analysis and venting considerations of existing buildings. The eventual end process here is to replace these dinosaurs with high efficiency sealed combustion systems, which doesn't completely eliminate the possibility of a CO case, but significantly alleviates it. And not all of these "candidates" will receive funding necessary to replace their dinosaur burners, and the CO potential may remain behind, so I feel it is important to address these situations.

I am certain that Timmy Mc will chime in here because I know he has a deep and great interest in educating people on CO, and how to eliminate the potential exposure, and I appreciate his input and wisdom in this delicate area.

The one common thread that I am finding on all of these projects is poor manufacturer designs as it pertains to appliance draft hoods, and inadequate/improper draft in the combustion zone that ends up creating their own set of problems as it pertains to the production of CO, and the eventual possible spillage of same. And what is even more important, is that what I am seeing in the filed is typical and representative of what is the "norm" out in the field.

Let's face it. If you have flame, you have CO. In all of my years of dragging combustion analyzers through the field, I have come across ONE appliance that had ZERO carbon monoxide in the flue gas stream, and oddly enough, that appliance was improperly applied. It was a small (< 75K tbuH) atmospheric cast iron boiler, that was missing its draft hood (bell shaped) and was directly connected to a masonry flue (unlined). And that is the ONLY appliance I have ever seen that had zero CO . Every other appliance I have inspected had CO to one degree or another in the flue gas stream.

Back to the draft issue. The fixed, integral draft relief hood, by its design and nature, is a physical disconnect between the main chimney, and the connected appliance. During my inspections last week, I was seeing ZERO negative draft at the appliance draft relief hood where flue gas samples were being drawn, and theoretically, in order for the combustion zone to work correctly, there should be at least -.02" W.C. pressure at that point.

Of the 8 natural draft appliances tested, NONE of them had ANY negative draft where they should have. There was typically a -.06 potential in the main chimney, but due to the design of the relief hood, there was nothing other than convection moving the required air through the combustion zone, and as a consequence, the excess air required for complete combustion was low, and the production of CO common.

So, we know what the problem is. What is the solution. The field "fix" is to block off the uncontrollable draft relief hood on the appliance, and install a properly adjusted double acting barometric damper on ALL appliances served by the chimney to insure that all of the appliance combustion zones are maintaining proper and required draft to do a proper and complete job of combustion. In order to do this correctly, it will require the installer to also install, or modify the roll out detection protection that is currently at the draft relief hood. Even under the utmost ideal of conditions, spillage from the relief hood is still a potential that MUST be protected against.

Now comes the scary part. Most manufacturers don't WANT us out there making field modifications of their appliances without their permission/knowledge. So I guess the question becomes, "Why are you doing what is known to not be the right thing in the first place?" Why are most all natural gas appliance manufacturers using the same known poorly operating draft relief method? Just because that is what everyone is doing does not make it right, does it? Why isn't the use of a barometric damper a standard?

I realize that the atmospheric appliance is headed the way of the Dodo bird, but there are STILL going to be a LOT of these beasts lying around in mechanical rooms throughout the world. I also realize that manufacturers probably will not comment on this issue for liability reasons.

There are significant benefits to fuel efficiency increases to be associated with this draft relief hood retrofit, and done properly, the extended liability to the contractor is really no higher than the potential exposure they are being exposed to right now.

Jim Davis with NCI has been my mentor on this subject for many years, and I am hoping that he will find his way to this thread and make comments, because I know he has had a lot of experience in this area.

There are a lot of other conditions that will cause CO production, even WITH proper draft conditions,and I would like to address those in a separate threads. I invite your comments here about the assumption of voided warranties as it pertains to field modification of the draft control systems. If you are afraid of liability, then I understand your not using your usual screen name, but please do comment. This is an area that affects everyone of us, and needs to be addressed by our industry as a whole.

Let's change this CO section from reading like an industry Obituary page to something that we can all learn from and actually save lives, AND increase efficiency and reduce energy consumption.

Lastly, many thanks to our host and his lovely wife for creating this section. Now, lets put it to use and make it do more than announce illness and death.

It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.


  • Al LetellierAl Letellier Member Posts: 402
    all these reports......

    Couldn't agree with you more on this issue, Mark. I see it all the time in my insurance inspection work. While oil is more common here in the Northeast, venting and combustion air issues make up a vast majority of the "soot and smoke" issues I see. I did investigate one fatal accident with direct vent gas appliance, and it was an installation issue.

    Maine has licensing for all the major mechanical trades but enforcement and permitting is seriously lacking with only 4 State inspectors and a handful of towns and cities that provide permitting and inspections. It is up to the individual technicians and employers to get trained and educated on the products they install and service, and it just doesn't happen to the level that it should. And as you mentioned, they simply don't understand the word LIABILITY because I see field modifications all the time.

    We need a stronger voice with the rule makers like NFPA to make the changes needed to save lives, not to just meet the needs of special interests in the industry. More hands on personnel need to be on those committees and groups like NAOHSM need to get involved in getting changes made at the grass root levels of our industry. Many business owners just won't invest in proper training of personnel. Let's just hope it doesn't take someone dying to wake up the powers that be that we need more effective rules and enforcement to make our industry as safe as it can be.
  • Charlie from wmassCharlie from wmass Member Posts: 3,925
    The issues I find

    Are split between no maintenance( the old gas never needs serviced myth is alive and strong) , or very poor installs some by licensed contractors and most by DIY's. The problem is real and the issue needs addressed but until their neighbor dies no one thinks it will happen to them. As child my father shared stories of CO poisoning, although we did not call it that and things only get addressed one customer at a time. We even have the old sewer vents tied into chimneys here in Mass. No one knows until they are actually in the attic or ripping out the bathroom walls that that galvanized iron pipe or cast iron pipe is rotted out and the boiler is venting in the home each time it fires.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Jean-David BeyerJean-David Beyer Member Posts: 2,532
    I am just a homeowner, but...

    I never had a CO detector in my house until I started getting symptoms of CO poisoning. It turns out I was really just coming down with the flu, but it scared me into getting a CO detector. When I got my new gas boiler, the inspector asked if I had a CO detector, and I said yes. He never looked to see if I were telling the truth or not (I was, and it had fresh batteries).  But since he seemed to think it important, I got an additional one for upstairs. So now I have two CO detectors, one on each floor, and two combination smoke detectors (both charged particle and photoelectric) one on each floor. So at battey change day, I need 3 AA cells for each CO detector, 3 AA cells for each thermostat, and a 9volt battery for each smoke detector.

    When I started reading about people dieing, or nearly so, from CO poisoning here, I suggested to some friends of mine that they should get CO detectors too. Because their daughter is like one of my kids (I do not have any actually). THey never got to it, so I finally bought them two. They put one in the basement, next to their oil boiler. I do not suppose that is the best place for it. The other one is upstairs, where they live. Some people would rather die than get detectors.

    I do not feel like paying for the annual service on their boiler, though. It is a small Weil McLain atmospheric oil burner.

    I do not envy the people in this profession, though. And I worry about those who seem undereducated in the business.
  • Mark EathertonMark Eatherton Member Posts: 5,584
    Well JD...

    You are proof that education works. If we only save just one life...

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Dan HolohanDan Holohan Moderator Posts: 11,877
    Thanks, Mark.

    Well said!
    Site Administrator

    [email protected]

    Hug your kids.
  • icesailoricesailor Member Posts: 7,265


    If this is a discussion about draft and CO, I'll comment.

    I have never understood the function of those Model "MC" Field double acting draft regulators. I do mostly oil and little gas. I have never seen a "M" control in place. When I first read about them, I figured it was to deal with a light off that created excessive positive pressure in the vent. I was taught and always understood that the function of a draft hood on the top of a gas appliance was to provide dilution air. Therefore, a function of a draft control on an oil burner (like an "RC") is to provide dilution air. Dilution air being that it cools down the exhaust gas. If a "M" draft control is opening to allow positive draft into the building, that is wrong! Boilers with draft hoods now have switches to shut off the boiler. They have roll out switches on the burner. I've seen them bypassed because they stopped the boiler.

    On a power vented gas boilers, the draft fan makes the dilution air. If you use a Power venter like SS-1 Side Shot, the PV makes dilution air. On power vented gas domestic water heaters, the power venter motor assembly is mounted over the top exhaust. Sucking room air and diluting it with the hot exhaust. I think that there are very few out there that truely understand draft and how it works. Especially masons who build chimneys. I have seen disasters that defie explaination. Where I work, it blows all the time at many different directions and wind speeds. I've seen the draft go back and forth in a chimney vent. High tech combustion testing is a joke. What do you set for? I once kept a Field PV runnibg by putting a sheet of plywood in front of it to deflect the wind. SS-1's will work here, but if you set the restrictor for low wind, it may not work and go out on the draft prover. Set it on the higher setting and you may have excessive draft over the fire because you may not be able to control the RC.

    Then, there is inside/outside atmospheric pressure. That's what causes all the CO problems. Want to know if you have a I/O pressure problem on a windy day? Look at the toilet bowl. If you see the water going up and down, that's changing pressure. It can drain a bowl and break the trap seal.

    I tell folks about this all the time and they look at me like I have two heads.

    The worst thing I ever saw.

    A gas boiler installed in a closet under a slanted roof. I was there to fix a leak on a super stor. I noticed the spillover switch sensor wire disconnected and laying on the top of the heater. I also noticed that the roll out switch was disconnected too. The closet was at the top of a set of stairs. There was a vent in the back wall to let air in but it opened into the knee wall space. There were no outside vents on either wall to the outside. Because the room was getting too hot, they installed a big roof vent fan run off a thermostat. When the room got hot, the fan started. When the fan came on' it sucked the air back down the chimney and out under the draft hood. When the boiler came on, the exhaust came out the draft hood, being blocked by the down rushing air. The boiler would shut off. So, they disconnected the spillover switch. Who would have thunk.

    Ask me about the guy from Vermont who went to jail for manslaughter in the deaths of a family who bought a home from him and had a problem that no one could define nor fix so he was told it was fixed. It wasn't, the new owners died, and he went to jail. I followed the story, incredulous that it happened, and no "expert" knew what really happened.

    I've been searching for years for an instrument to measure pressure differential in a house. I'm missing something though.

    Just a tired old plumber,

  • Tim McElwainTim McElwain Member Posts: 3,904
    Mark do you sometimes feel

    all alone? After many years of preaching about CO and related issues I am seeing some very gradual change but certainly not enough nor are they fast enough.

    As you know it is not easy to accomplish a design change on a customers equipment by removing the draft hood and installing a barometric. When I was with the gas company it was never a problem as we had somewhat of an AHJ status. Since leaving on several occasions I have had systems red taged by the same utility I once worked for because the draft hood was missing

    That being said the biggest problem we face as far as I am concerned is education both of homeowners and trades people. Every trade show I attend is heavy on how to sell, how to make money but very little about gas safety or CO education. Maybe we should get Dan to start teaching on the subject as he gets more exposure to the trades than any of us.

    Many who are out there everyday in the trades are entering facilities with no idea as to the possible level of CO which could kill them. They have no protection whatsoever.

    I plan to comment more in this area but I am getting ready to leave for some seminars I will be conducting next week. I too look forward to Jim Davis chiming in here perhaps.
  • Jean-David BeyerJean-David Beyer Member Posts: 2,532
    I would not notice if I died from CO poisoning, but ...

    ... I would be devastate wer emy now 14 year-old friend would get it from CO in her own house. It would be the worst thing that could happen to me.
  • SteamheadSteamhead Member Posts: 11,384
    As I understand it

    with a LOT of help from Tim, I might add, and I hope I can say my lessons well.......

    The draft hood was designed around atmospheric burners with standing pilots. If there was a downdraft, it went into the boiler room rather than the firing zone where it could snuff out a pilot or main burner flame. Since the traditional thermocouple pilot safety is allowed three minutes to respond to a flame outage, that could result in a substantial amount of gas being released into the appliance, which could cause an explosion.

    If a barometric was used with an atmospheric burner, or any burner that had a pilot light, it was supposed to be a double-swing type and be mounted in one end of a bullheaded flue tee. The flue pipe from the boiler came up into the bull of the tee. That way, a downdraft would travel thru the run of the tee and swing the barometric open, bypassing the firing zone.

    Now we have more-advanced flame-retention power gas burners which have fast-acting electronic safeties and spark ignition, and can produce some measurable static pressure. So the chance of a flame failure from a downdraft is greatly reduced, and if it does occur the safety can shut the burner down in less than a second. A double-swing barometric is still required for these burners though, and all gas burners should have blocked-flue safety switches.

    So why do we still see draft hoods? "Well, we always did it that way".......
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Mark EathertonMark Eatherton Member Posts: 5,584
    Absolutely open to discussion!!

    I will speak to my knowledge as it pertains to natural gas, natural draft appliances.

    These appliances require a means of moving air through the combustion zone. Without this required draft, inadequate secondary and sometimes inadequate primary air is introduced into the combustion zone to allow for a complete and efficient combustion process. The appliance manufacturers know this, but what is worse on their equipment is excess draft, pulling the flame off the face of the burner and pulling so much secondary air through the combustion zone and the heat exchange zone that the heat doesn't get a decent chance of transferring from the hot flue gas to the surrounding heat exchange surfaces. Most of the heat exchange from the flame is in the form of radiant heat, but in order to maintain the delicate balance necessary, a LITTLE draft (-.02" W.C.) at the appliance outlet is necessary. The problem is, that by its nature, the draft relief hood RELIEVES the excess draft, AND the minimal draft

    (-.02"W.C.) required to draw the combustion products and required air through the process. In other words, their hoods work fantastic at disconnecting the combustion chamber from the chimney's significant draft, but it does a terrible job of maintaining the required minimum draft through the appliance as a whole.

    As Frank (Steamhead) pointed out, the reason for the double acting barometric damper on gas fired equipment is to avoid a down draft condition. The code approved method of avoiding an going dangerous spillage from the draft hood is to install spill detection switches wired in series with the safety circuit.

    There is absolutely NOTHING we can do to stop ignorant consumers from bypassing these critical safeties, other than the US requiring annual inspections on ALL fired equipment, like they do over in Europe. I know it makes the hair stand up on the back of some peoples neck when I mention this, and I am not a big fan of government intervention, but this is one area where I feel it is justified for more reasons than just the safety aspect.

    As for pressure differential between the inside and the outside of the house, if the mechanical room is set up with the proper amount of combustion air, there should only be atmospheric pressure differential, which is always higher at the base of a stack then it is at the top of the stack, except for wind induced differentials.

    As for checking this pressure differential, I have Dwyer magnehelic pressure differential gage with a HI and LO pressure port that reads in 100ths of an inch water column pressure, with a maximum reading of 1/2" W.C. pressure. With enough 1/4" plastic tubing, you can put one end of the tube outside, and run it to the gage inside, and read the actual pressure differential.

    As for bouncing traps, that IS wind induced pressure differential, and it is not the norm, but if you have a properly installed venting system, with the proper combustion air, and proper draft control with required spill detection you shouldn't have any problems. Key word in that last sentence is SHOULDN'T. I have had systems that had EVERYTHING they needed, and still were problematic during excessively windy conditions. I don't think there is an appliance on the face of this World that doesn't have SOME kind of problem during windy conditions tho...

    It is VERY important, that before you modify a natural gas appliance with a fixed draft relief hood by installing a barometric damper, that you run it by the authority having jurisdiction AND the fuel supplier.

    Here's where it gets strange. Most appliance manufacturers do NOT want us out in the field "modifying" their equipment. But if we worked on it last, and we don't modify their equipment to get it to work correctly, and a CO situation occurs, and God forbid, someone gets sick or dies, who do you think is going to be the first person named in a wrongful death lawsuit? YOU!!

    The manufacturer might be co-named, but your name will be on the top of the list of defendants.

    If you found a dangerous situation and were totally aware of it, and someone got ill or worse due to your inaction, you can bet your bottom dollar that your name will probably be the only named defendant...

    If you found a dangerous situation, and you took the initiative to perform a recognized, code approved draft/spill control procedure and something still unfortunately went wrong, the jury is going to take this action into consideration when the hammer drops.

    I would rather take my chances with a jury by performing due diligence.

    I would like to think, that most reputable appliance manufacturers would welcome the actions of installing a draft regulator and spill detection system if it was intended to increase the appliances efficiency and negate the production of carbon monoxide. Remember, these people (manufacturers) have a bevy of lawyers that are continually scrutinizing their every move, looking at it from the litigation potential end. They are also under the continuous scrutiny of approval agencies.

    Remember when FVIR water heaters became mandatory? That was due to a Senators family member being caught in a flash fire caused by the spillage of flammables in the near vicinity of a tank style water heater. I suspect, that had some Senators daughter been maimed or worse from CO poisoning, we would have a completely different protocal to deal with.

    As Frank so eloquently put it, "That's the way we've always done it". Guess what. It is time to change.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Mark EathertonMark Eatherton Member Posts: 5,584

    There are times that I feel like it is an uphill battle. In times like those, I think about your and Jim's and other educators contributions, and realize that we MUST continue this ongoing battle.

    What I don't understand, is why some of the most knowledgeable contractors on the face of the Earth continue to ignore this potentially deadly situation. If they were smart, they would realize that there is a LOT of potential money to be made AND saved with the installation of these devices, and the service of these appliances. And what a great feeling knowing that we are out there saving lives and reducing energy consumption.

    Thank you for your ongoing support and education of our industry.

    I am still learning, so if I say something that doesn't set well with you, please speak up.

    Thanks a million.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Tim McElwainTim McElwain Member Posts: 3,904
    Why do we always

    have these great discussions when I am on the way out the door to do a week of seminars, Oh well maybe I can jump in when I get back.

    Well said Steamhead you were one of my best students and now you make it work in the real world. That is the most rewarding side to teaching is to see students apply what they learn and make it work.
  • Jim DavisJim Davis Member Posts: 578
    Drafthoods & barometrics

    The function of drafthoods and barometric is not dilution air.  Power venters do not bring in dilution air unless a barometric is installed with them.

    Drafthood specifically were designed to prevent downdrafts from blowing out pilots.  However they were never really tested for any unsafe conditions which they allow. If you have a downdraft then all your flue gasses are venting into the building,  Do we really want to keep the equipment running?

    Barometrics are designed to control the amount of combustion air going into the burner under most conditions not dilution air.  Draft is constantly changing therefore the air to the burner would be constantly changing and this causes unstable combustion.

    Barometric should be double-acting on all fuels including oil or especially oil.  An oil burner lights with extreme positive pressure which needs to be relieved.  By the barometric being single acting this pressure blows back into the burner tube.  If they were double-acting and there was real spillage a spill switch would be effective in shutting the oil down.  Never saw how a single acting barometric kept a building from sooting up when the flue was clogged.

    There are wind caps available for sidewall venting called Star Kaps(Field Controls) With these power venters and barometrics are easily setup. 

    It is easy to see there is a need for a lot of education out there.

  • Jim DavisJim Davis Member Posts: 578
    Carbon Monoxide-Licensing, Codes, Inspectors

    Most of the CO incidents or problems I have been exposed to for the past 30 years were installed by licensed contractors, installed by manufacturers specs and codes.  And like a Code official would know if a job was working safe or not.

    As long as codes give inanimate objects the ability to make decisions, there is going to be a problem. 

    Based on a GAMA magazine article in 2005, no one on the code board ever had any hands on field experience and they felt that contractors that worked in the field might add to the code writing experience, but not necessarily.  Talk about egos!!!
  • Jim DavisJim Davis Member Posts: 578
    Making Equipment safer

    IN 1980, I was the first person ever to do a continous CO flue gas sample in the field on conventional gas equipment.  It was then that I first discovered the dangers of drafthoods.  It was also when I started teaching contractors in my area to get rid of them whenever possible.  However, without a continous sampling combustion analyzer this could not be done safely then or now.  Most contractors in the field didn't have this type of equipment for another 10 years.

    In 1993, AGA Labs spent a week in the field with myself, my students and Field Controls to test the safety of drafthood appliance installed by licensed contractors, according manufacturers specs and code.  18 out of 18 appliance failed to run safe under any condition with drafthood in place.  Then the drafthoods were replaced with barometrics, with no additional changes to the equipment in any way.  18 out of 18 tested 100% safe under all conditions.

    Shortly after this, AGA Labs discontinued certifiying gas equipment and let the Canadians do it and they left town.  It went from AGA to CGA.

    December 2009, Air Conditioning NEWS, GAMA Warns Consumers Against Equipment Modification.

    This is and was a direct attack against NCI and my training.  I have their original letter to the editor stating they do not condone improving the safety of equipment.  In the News they state that equipment is safe enough and has been tested for a variety of conditions.  However one condition they are never tested for is field installation.  That may be why they have had over 40 major recalls in the last 10 years on new gas appliances.  I really need them to tell me what to do.  I have never been afforded room to make one mistake and they have no limit.

    When a manufacturer and contractor are involved in a law suit guess how often the manufacturer defends the contractor versus covering their butts.  Never.

    The manufacturer doesn't own the equipment once it has been purchased.  They are not responsible for its installation and operation-we are.

    The National Fuel Gas Code state the agent of the owner is the Authority Having Jurisdiction versus Authority Having Ego.
  • marsmars Member Posts: 87
    State law in Colorado now being enforced.

    Mark I am sure you are aware of the new state law that mandates co detectors be installed when ever a fuel burning appliance is replaced in Colorado. I had an inspection in Brighton and passed the mechanical side but was made aware that there needs to be a co detector within 15' of any bed room. I did some research and the law puts the responsibility on the home owner? Now after the inspector brought this to my attention I ran some Co detectors up to my clients house, but that being said why would the legislature put that responsibility on a home owner. This I do not understand. Just wanted to share this story as it blindsided me as to the new legislation, I had not heard a word from my wholesaler, or any other source. Mars      
    Matt Rossi
  • Mark EathertonMark Eatherton Member Posts: 5,584
    Very interesting Matt....

    Finally, the politicians got something partially right.

    The law can be reviewed at

    and there is a section, as you stated, How does this law affect those who live in single-family homes after July 1, 2009?


    For any home offered for sale or transfer, this law requires that an operational carbon monoxide alarm be installed within 15 feet of the entrance to each bedroom (or other room lawfully used for sleeping purposes), or in any location otherwise specified by a state or local building code. This requirement must be included in the listing contract


    For any home where a building permit is required to address interior alterations, repairs, addition of bedrooms, or the addition or replacement of fuel-fired appliances, this law requires that an operational carbon monoxide alarm be installed within 15 feet of the entrance to each bedroom (or other room lawfully used for sleeping purposes), or in any location otherwise specified by a state or local building code.

    As for having the homeowner do this installation, that sounds like the HBA doing their usual job of putting the cost and responsibility on someone other than themselves or their members. As a good and responsible contractor, you should just include the cost of a detector in your bid and explain to the consumer that it is required by the new law, but that THEY are responsible for future maintenance (batteries) and future replacements.

    It would probably be a good idea for any Colorado wholesalers to include CO detectors in their product lines to keep people like you away from Home Depot...

    It would probably also be a good idea for the State to contact wholesalers with a letter to know how the law reads. I wasn't aware of it.

    Thanks for sharing.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Mark EathertonMark Eatherton Member Posts: 5,584
    edited October 2010
    Ice Sailor...

    Dillution air is a side effect, not a wanted effect.

    With a fixed relief hood, you don't control the dilution air, it controls you. And it effects everything you do there AND downstream. If the combustions not right, nothings right. If you don't test, you don't know.

    I've had boilers with code require vent and relief air, and the vent would condense (82% appliance connected) in the middle of the winter. Fixed hood letting TOO much cold duh-lution air into the flue gas stream. If you haven't got a good and properly sized heat exchange area, everything will be for naught, but I've never seen THAT condition :-)

    We installed baros. block the fixed hood, and all the problems went away and his bill dropped about 15 to 20 %. It's basic efficiency.

    Thanks for chiming in.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Mark EathertonMark Eatherton Member Posts: 5,584
    Thanks Jim...

    I really appreciate your coming by and making comments and answering questions. You are an industry treasure fer sure.

    What are the typical fuel savings (range) for these retrofits?


    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Jim DavisJim Davis Member Posts: 578
    barometric savings

    The addition of barometrics give us total control of air to the burner.  With air under control is is now possible to adjust the gas to match this amount of air.  Normal savings can be 4% to 12%.  However, the safety of equipment and reduced maintenance of equipment is worth the modification.  Savings is just a bonus. 

    A water heater in a flue with a drafthood may condense.  The same water heater modified with a barometric will not, regardless the size of the chimney.
  • icesailoricesailor Member Posts: 7,265
    CO detectors:

    CO detectors have been a requirement in Massachusetts for a while and there haven't been any problem with it. If you sell a house and it has fossil fueled equipment, you must have them. If you replace a fossil fuel appliance, you must get them.

    End of discussion.

    Because MA requires smoke detectors in all buildings, they tie right in.

    No CO dectors in inspection, no sign off. End of discussion.
  • Charlie from wmassCharlie from wmass Member Posts: 3,925
    A level playing field makes codes easier to enforce

    Like Icesailor said it is simply required end of story. Regulation and enforcement of the regulation is the only way things will improve. Some areas have a lot of infrastructure to build before they can enforce the codes, this is the sticking point I see. Here in MA we already have a well developed code enforcement body. Adding CO to the list was easy by comparison.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Mark EathertonMark Eatherton Member Posts: 5,584
    edited October 2010
    It should be a National requirement...

    Carbon Monoxide has been called the most avoidable means of inadvertent poisoning.

    People don't have to continue dying from CO poisoning. Education is important, but not as important as checking the appliance for proper operating, and repairing as needed to correct any deficiencies.

    Testing is important, but know what to do to correct the situation is just as important as discovery, and THAT is not rocket science.

    For example, yesterday during an inspection, I came across a boiler that had 2474 ppm air free CO in its flue gas stream.

    Here are its numbers, PRE emergency service.

    O2 = 11.2

    CO = 1143 ppm

    Efficiency = 74.1%

    CO2 = 5.5 %

    Stack temp = 428 F

    excess air = 103.1%

    Air Free CO = 2474

    The burners were extremely dirty, misaligned and generally dirty.

    After pulling burners, and cleaning them and properly reinstalling them, the numbers were,

    Post service RETEST

    02 = 7.3%

    CO = 19 ppm

    Efficiency = 79.1 %

    CO2 = 7.7%

    Stack temp = 456 %

    Excesss air = 47.3%

    Air Free CO = 29 ppm.

    This appliance was NOT spilling any of its products of combustion into the room, but all it takes is a wind from a certain direction, to cause spillage, and death and devastation... I was technically required to shut down the appliance, disable it and demand immediate attention. This was in a Senior citizen retirement village, and it was 20 degrees F outside. I called the service company of record and told them about the situation. They got someone on it right away, and corrected the situation. Had they not been able to show up, I would have performed the burner service myself, before I would have walked away.

    I should also note that there was ZERO draft detected at the top of the combustion zone. There was -.05" W.C. potential in the chimney, but due to the crap draft relief hood, there was no draft available to properly draw air through the combustion zone, hence the low excess air on retest. The excess air on the initial test was high due to the incomplete combustion that was occurring, as is backed up by the significant CO.

    I am hoping that Jim will drop by and give his interpretation of these results, but it is obvious that this appliance was in serious condition.

    The sad thing about this is that the service man said his company has ONE combustion analyzer for four company trucks, and that it spends most of its time in the office, unless they are commissioning a new piece of equipment. Plus, he said he was the only person that was really qualified to look at the results, and make proper recommendations to eliminate the condition.

    In conclusion, If you don't test, you don't know. There was NO carbon deposits ANYWHERE on this boiler. No external indications of a problem.

    Secondly, and most importantly, knowing what to do to eliminate the excess production of CO is key to owning and operating an analyzer.

    So, if you don't test, you don't know, and if you do know, you need to know what to do to eliminate the production of CO.

    BTW, this system is being replaced with a sealed combustion modcon boiler in the near future...

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Jean-David BeyerJean-David Beyer Member Posts: 2,532
    I am really starting to wonder...

    I bought a pH meter because I could not get reliable readings with pH paper. I could also use it in my photographic darkroom, thought I do not really need it there.

    You report on a service company that has one combustion analyzer for four service trucks.

    When I had a new boiler installed a year and a half ago, they did not use an analyzer to set up the burner. When I protested this, they said it comes pre-adjusted from the factory. I sure hope so.

    One year later, when time for my first annual service, the guy had no combustion analyzer, no way to measure boiler pH, no torque wrench for the aluminum heat exchanger bolts, and would not even check the water in the condensate trap. All he did was look into the inspection window and said everything was fine. I tried to complain to the company, but never got my phone calls, my e-mails, and my regular mail answered.

    So I got a new heating contractor. He did much better, but I had to loan him my torque wrench. He had only a wet combustion analyzer and he said he could not use it on a condensing boiler because the condensate would harm the oxygen sensor. I do not know what he was talking about, but he may have been right.

    So now I am trying to figure out if I should buy a combustion analyzer. Since I am a homeowner, I should not need to buy one of these things. And their sensors do not last all that long. I mean, they seem reasonable for a professional who I imagine would use them several times a week, but for me using it once a year would not seem cost effective. Why this reluctance to have a digital combustion analyzer on every truck, with someone trained to use it?
  • icesailoricesailor Member Posts: 7,265
    CO Infrastructure:

    Here in MA where many consider us a perjorative term, we were the first in the USA to have a plumbing code. Because they needed to have standards for relief valves. When copper water tanks proved that 1 cup of water would instantly convert to 1200 cups of steam and flatten a three decker home. With a tank launching in the cellar and continuing out through the roof.

    Speaking of testing, it is understood by those of us in the business that for our insurance to cover potential damages caused by faulty conbustion (like sooting up), you had better have done a combustion test with a analyzer that has a printer that shows that when you left, it was OK. If not, and it soots up, you are on your own. Ask your insurance company about it.

    My wet bulb is more accurate but doesn't do all that a electronic analyzer will do. My writing out the results on a card I fill out doesn't cut it. A oil sales and service company I deal with has their techs staple one copy to the slip they leave behind, and another for the company files.

    You may  not like it, but that's the way it is.

    For you anti-government guys out there, this isn't mandated by the State or Locals, it is THE INSURANCE COMPANIES!!!

    They run the show. Not the government. What they TELL you to do, You do.

    So, get out your check books. Get professional. Buy a analyzer.

    "There's never enough time toi do it right. But always time for someone else to do it over."
  • Jim DavisJim Davis Member Posts: 578
    bad contractors

    Wow, you are a magnet for attracting bad contractors.  Analyzer have water traps to keep moisture out of them.  All flues have water vapor in them.  Looks like you need to find another contractor because this one sounds like he should work for P.T. Barnum.
  • Jim DavisJim Davis Member Posts: 578
    Senior Center Boiler

    I wonder who serviced that boiler before you tested it Mark??  Nursing Homes, Retirement Centers, Senior Homes are Number 2 on my most dangerous buildings in the country right after hotels.

    The change in O2 may not just be from the CO but there had to be some unburned raw gas also.  Was it dirt or rust?? 

    I am guessing there was no safety switch on the hood in case the flue gets blocked.  I can't teach techs to get rid of drafthoods fast enough.

    I assume the O2 and CO were stable during both tests.
  • Mark EathertonMark Eatherton Member Posts: 5,584
    Rust, dirt and misalignment

    The burners had been submerged during a flooding incident last Spring.

    The burners were also misaligned due to improper installation of the pilot assembly, which caused the outside burner to impinge flame on the refractory wall.

    O2 was fairly stable after 5 minutes of burn time.

    While I have you on the line, what is the difference between CO and air free CO? I think I know, but would rather hear it from the Guru of Partially Burned BTU's. :-)

    Thanks Jim.

    I hear you about barometrics...

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Jean-David BeyerJean-David Beyer Member Posts: 2,532
    So, get out your check books. Get professional. Buy a analyzer.

    Trouble is, I am NOT a professional. I do not want to be a professional. I have already learned a lot more about hot water heat, about mod|con boilers, etc., than I, as a homeowner, should need to know. I researched contractors before picking the one who installed my new boiler. Dissatisfied with their maintenance procedures, I researched contractors again and picked a second contractor. I wish they were listed in the telephone book, sorted by specialty (installation & maintenance, oil & gas, forced air & hot water & steam, etc.) in decreasing order of ability. That will never happen, of course.

    The one I got rid of says 30 Service and Installation Vehicles, NATE, BPI, PLU License Number xxx, Elect License Number xxy, in business since 1968. This one refuses to follow the maintenance instructions given by the boiler manufacture, the very manufacturer they recommended for me to have instaleld. They also say that the boiler additive (X-100) specified by the manufacturer is unnecessary.

    The new one says NATE, they have been in business 55 years, Energy Star Partner, MSCA, ACCA, two Chambers of Commerce, and have an impressive list of clients, inclucing 8 churches and synagogs, 11 boards of education, 7 Federal agencies (post offices), 7 municipalities, 12 "commercial and industrial', and 3 non-profits. At least, this one says they will follow the instructions of the boiler manufacturer, and they say this in writing in the service contract. They asked if the X-100 had been put in, I said no, and they automatically put it in.

    Trouble is, it does not say if their crews have digital combustion analyzers and know how to use them.
  • Tim McElwainTim McElwain Member Posts: 3,904
    Mark I would have thought

    the equipment would have been replaced due to flooding. Both FEMA and GAMA recommend the replacement of any equipment that has been flooded.

    Concerning CO and Air free CO readings on an analyzer my take on that is that the air free will always be the higher reading as it is an actual calculation which eliminates the oxygen, carbon dioxide and in some cases the NOX from the mix to give a pure CO reading. Before we had analyzers we would use either a formula based on either the CO2 wet kit reading or the O2 wet kit and a very inaccurate test ampoule for CO to get a better handle on actual CO. The combustion analyzer now does all that for us. Some analyzers (Testo I believe) actually calculates the NOX out of their readings. I am sure Jim can give any correction to my take on that.

    By the way the Field testing that Jim talks about that was done with AGA prompted us at Providence Gas to buy a very expensive electronic analyzer ( I can't remember the make and model) for use on all of our large burner applications. We had been experimenting with replacement of draft hoods on some dual drafthood commercial water heaters at the time. Our research on doing conversions from oil to gas really got us interested in draft hood replacement on design gas equipment. In 1978 we actually converted four commercial water heaters in East Providence RI to barometric operation. A lot of the research was done with a PE from Midco by the name of Tom Roche. Some of our research was included in the Gas Engineers Handbook.

    We later had problems with GAMA and several manufacturers who did not want alteration of flues and draft hood removal on any equipment. The gas company took it upon themselves however to accept responsibility for such actions.

    In recent years National Grid has red tagged 7 of my alterations on design equipment and twice brought me before the local authorities for chastisement. In all of those cases actual testing in the basement has proved beyond a shadow of doubt that what I did improved and resolved safety issues on the equipment. All seven of the red tags have been removed, however I was instructed not to alter any more equipment.

    I just got back in the office after 4 days away so I want to read all these postings and hopefully give some comments.

    I would like to add a word of warning here, that is no technician who has not had training on doing this alteration of draft hood to barometric on design equipment should undertake this. You definitely need to have attended Jim's or my training before messing with design functions of equipment.
  • Mark EathertonMark Eatherton Member Posts: 5,584
    It was a minor flood Tim...

    A break in the water service serving the building, and a failed sump pump caused the water level to go to about 6" deep in the basement mechanical room. The burners sit about 4" above the floor. Due to the fact that none of the electronics got wet, they assumed it was OK to restart without checking. "If it's hot, don't mess with it..."

    Why show the different CO readings, and which one is more important and relevant to safety? I understand the dilution factor, but which reading means the most to us in the field, the "potential" CO (air free) or the "diluted" CO?

    Still learning, and thank you for taking the time to teach us.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Tim McElwainTim McElwain Member Posts: 3,904
    edited October 2010

    is the real CO or actual CO with out contamination from oxygen and CO2. It is the most important reading to us in the field. It was called the "Air-Free Factor in the past. Since the flue gas contains varying quantities of air and CO2 (depending on the percent excess air) the carbon monoxide limit is usually specified on an air-free basis. The air -free factor is the ratio of the ultimate CO2 percent of the gas being burned to the actual CO2 percent in the flue gas sample.

    Thus for say natural gas the ultimate is 11.7% this along with the actual measured CO2 in the flue sample (typically with a wet kit in the past it was an actual reading) today CO2 is usually a calculated reading by the analyzer unless it has a CO2 sensor. So as an example lets say we had a flue gas sample reading of say 8.8% CO2, with a carbon monoxide sample of .03% (300 PPM) in the actual sample it would be:

    11.7% divided by 8.8% then multiplied times .03% = .04% (400 PPM) in an actual air-free sample.

    There is a similar procedure(formula) for using the O2 reading. Today the analyzer does all that for us electronically. The reason they give both is so you have a reference point for real versus contaminated.

    The ANSI standard for Boilers, Furnaces and water heaters is 400 PPM air free in a flue gas sample, what is often called the maximum allowable level. We want to see no more than 100 PPM on both gas and oil unless specified otherwise by manufacturers instructions.

    The ANSI standard for gas cooking ovens is 800 PPM and remember most of the time that is venting into your kitchen unless you have a range hood. Today with all the commercial cooking equipment many folks have in their homes the cooking range needs special attention when you are doing testing in the customers home. YES YOU ARE REQUIRED TO TEST OVENS ON COOKING STOVES AND ALSO DECORATIVE APPLIANCES, DRYERS ETC.
  • rlaggrenrlaggren Member Posts: 159
    Flue gas readers are central to improved installations

    These instruments are central to the issues and measures discussed

    above. So how effective and useable are they? How finicky? Equipping a

    truck is a significant expense to a business and something that costs a

    lot and doesn't do the job easily and often or breaks down expensively

    isn't going to be snapped up. And that puts paid to the idea of wide

    spread use of flue gas measurements. At least until GOD in the form of

    insurance companies and administrative authorities eliminates all who

    sin; even then if the tool is difficult and picky to use and maintain

    the results will not be as good as they should be.

     Do they need to be stored in air conditioned padded boxes to be

    reliable? If they get, say, dropped out the truck door while unloading

    do they still read accurately? How easy is it to contaminate their

    sensors, say just by touching one? All the above relates to the chances

    of the one used by a tech actually returning readings meeting its

    specifications. Which in turn relates directly to the value service

    companies and customers might reasonably expect. Which relates directly

    to the likelyhood that these fairly expensive instruments will become

    standard in every truck, suffering the normal abuse and bad luck such a

    life implies. Oh, and how often do they need to be calibrated and how

    long does it take? One day every month?

    On a slightly different slant: Curious if there is an easy way for a customer to get an indication of the quality of the measurements, assuming that their service tech takes them. A print-out was mentioned and that seems like an excellent document.

    My question is what info the "header" of the printout shows. Eg. I assume it shows date. Does it also show make/model of the instrument? Does it show when the last calibration was done? The make/model would give some indication of the accuracy and and possibly the condition of the instrument (a 10 yr old instrument might not be credible). The calibration date would give some indication whether the instrument was maintained properly and thus whether the readings were reliable. A customer would not know the particulars for an instrument off-hand, but that is info that would be available fairly easily to them or other pros involved.

    So: What "administrative" info do these instruments print and to what extent is it settable by the  person using it?

    disclaimer - I'm a plumber, not a heating pro.
  • Charlie from wmassCharlie from wmass Member Posts: 3,925
    Our policy has become more cut and dry and perhaps cold hearted.

    If we come upon equipment that has been flooded it gets replaced or they call someone else. My understanding was it was national gas code flooded equipment needs to be removed from service and replaced. It could be just our local inspectors take on the code. I have seen several units I repaired from flooding years ago need more in parts than they cost back when they were installed new.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • SteamheadSteamhead Member Posts: 11,384
    edited October 2010
    On our Testos

    the printout shows the make and model of the analyzer, the date, time and I believe the analyzer's serial number too. We give the customer a copy and also keep one for our records.

    Maybe some of the early units were difficult to use and maintain, but they've gotten a lot better.

    Bottom line is, if you work on a combustion unit and you don't have an analyzer, you're naked. That is not a pretty sight...............
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • SteamheadSteamhead Member Posts: 11,384
    Thanks, Tim

    I am lucky to have had such great teachers. 
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • SteamheadSteamhead Member Posts: 11,384
    edited October 2010
    ANSI allowable CO levels are too high

    "The ANSI standard for Boilers, Furnaces and water heaters is 400 PPM air free in a flue gas sample, what is often called the maximum allowable level. "

    "The ANSI standard for gas cooking ovens is 800 PPM."

    If anyone reading this concludes that these CO levels are acceptable just because ANSI allows it, this is dead wrong. No pun intended, this much CO is fatal.

    I seem to remember that these levels were established in the early 20th century sometime, maybe the 1920s. If so, they are sadly outdated. Buildings of that vintage were drafty enough that CO could dissipate. Today buildings are tighter, and if CO gets into them, it stays there.

    Also do not forget that CO is the result of incomplete combustion, so it is a waste of fuel. It follows that CO will BURN if it has the right amount of air available. If you've ever watched a building on fire where part of it suddenly erupts into flame, that's usually an accumulation of CO and smoke which just got the right amount of air and heat to ignite. 
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Jim DavisJim Davis Member Posts: 578
    Air Free CO

    Sorry, when I am on the road I can't always get back, even if it seems like I am on line.  Timmy explained "Air Free" correctly.  If we could measure the CO right in the flame before it mixes with Excess Air around the flame we would get the actual CO the flame is making.  This can't be done so it is calculated assuming some values.  Some Combustion Analyzers have a NOX filter(TESTO & TSI for sure).  NOX will cause the CO sensor to read higher in many cases which means no two analyzers will give you the same "As Read" or "Air Free" calculation or reading.  And sometimes the analyzers with NOX filters read higher CO than those without which adds to the confusion.  I calibrated a Testo, Bacharach and TSI one day with 100ppm of Cal Gas and then using one probe, checked the CO in the flue gas of a water heater.  They all read different.  O2 and temperature readings were the same. 

    "Air Free" is the ANSI standard for equipment when it comes to its rating.  These ratings are quite high.  The problem in the field is that not everyone has an analyzer that measures O2 and there are the ones that the O2 sensor goes bad and you can't get an "Air Free" calculation.  Because of this I teach to use the "as read" CO because it is always there.  I train home inspectors, fireman, Hers raters etc., and they only have CO analyzers.  If you keep your "as read" CO below 100ppm and your O2 between 6% & 9%, the "Air Free" will be between 140ppm and 180ppm approx.  These are well below the ANSI standard.  It is not equipment making high CO that kills people(except unvented) it is equipment that is spillling.  When this is happening it doesn't matter how low the CO might be at the time because it will eventually climb higher than we can read, usually at night when everyone goes to bed.

    The biggest problem out there today is people trying to reduce CO to levels that screw up the efficiency of equipment and can cause more wear and tear and make them even more unsafe.
  • Jim DavisJim Davis Member Posts: 578
    Combustion Analyzers

    Working on a fuel burning appliances without acombsution analyzer is like going to a dctor that doesn't have a stethescope, blood pressure tester or a thermometer.  Just checks your color, height and weight and your good to go.

    Obviously rumors about how I treat combustion analyzers hasn't reached youu yet.  My students have to duck as I throw it across the room.  I bang it on tables and the floor.  Stays out in my car in the cold and heat.  I don't expect techs to treat them that way but when someone asked for my input on analyzers the first thing I make sure they can do is ride around on a service truck.

    I bet you have some nice refrigerant reclaimers that weren't cheap.  You probably get to use them once in a while.  Wonder how many lives they save or how much more efficient they make an A.C unit.  Then we charge our customers when we use them,  A combustion analyzer can make equipment safe and efficien, assuming one has been trained on their proper use.  Very few manufacturers of these actually know how to use them propely in the field.

    Techs who are trained to use them properly can bring in an extra $5000 a week in service and replacement work.  It is not the tool that matters, its the person using it.  Once every couple of years they need service and calibration, most of which you can do yourself on many units.  I do not recommend ones that you can't repair yourself.

    Factory specs are for techs that don't test or measure.  They have so much slop built into them anyone can put them in and make them run.  Only Pros can make them run safe and efficient.
  • Mark EathertonMark Eatherton Member Posts: 5,584

    There are a BUNCH of testers on the market. And they ALL have features that some are specific to the manufacturer. That question (Which tester is better?) has been asked and answered on this forum a LOT in the past, and there is no common answer, other than "It depends". They are all good, but some are better than others. They all require sensor replacement. I've owned Testo, Bacharach and others, and while I prefer the Bacharach, others prefer others. Don't worry about the "administrative" information given on the read out. If you are doing due diligence, the tester will be accurate enough to know when you are in trouble. And as all the mentors have said, just owning the equipment is not enough. You MUST be able to understand and interpret the readings you are receiving, and know what needs to be done to correct it. In most cases, it is going to be a draft issue, which can be properly addressed through the proper and safe application of barometric dampers and spill switches, but in some cases, it has to do with fuel pressures, make up air, negative pressurization and others.

    I would suggest that you take either Tim or Jim's class, and take that information out into the world, with trained employees, and become an expert in the production, elimination and prevention of this deadly killer, and there is nothing wrong with making a profit at it. Nothing.

    In most cases, your services will pay for themselves in the form of energy savings.

    As for cold storage, I suggest that in cold weather climates that the device be kept warm. Not because you HAVE to, but because if you bring an ice cold instrument into a warm humid environment, dew will form on the printed circuit boards of these devices, and electricity and moisture don't mix.

    There are a LOT of things in service trucks that are NOT supposed to be exposed to freezing conditions. I keep a "Hot Box" of these items, and if it is going to get extremely cold, I bring it into the house with me at night to keep them safe.

    Thank you for asking these important questions, and thank you for considering doing the right thing. You will not regret it.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
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