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Barometric Damper Upgrade to Atmospheric Gas Steam

crash2009
crash2009 Member Posts: 1,484
I have been thinking about adding a barometric damper to an atmospheric gas steam boiler.  From what I've read, here on the Wall, I should be looking for a double swing type, mounted at the end of a bullheaded flue tee, and have a blocked flue safety switch.  

Is this necessary to fine tune the flame of the burner? 

What brand and or model number would you recommend?

Any other advice you would recommend?

Am I just wasting my time looking into this?

Here is a little info on what we presently have 16" X 8" (1/4" screen) fresh air intake 80,000 btu/hr water heater, Weil Mclean EG55 200,000 btu/hr, there is a draft hood and Effical electric damper.  The chimney is brick, about 40 feet tall, appears to be lined.  Based upon the breeze that comes in the fresh air intake, the chimney drafts very well.

The steam system has been just about re-everythinged, is running very well.  I wanted to get a burner man over here with an analyzer and I thought the barometric might make things easier to adjust. 
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Comments

  • JStar
    JStar Member Posts: 2,752
    RE

    You only need a barometric damper if the boiler is drafting too much. I would do the combustion analysis first to decide if one is necessary.
  • Henry
    Henry Member Posts: 988
    Manual

    Your I & O manual has all the information that you need about your boiler. But, if you have a draft hood, you are not allowed to install a barometric damper! The draft hood is self compensating.
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Double Acting Gas Barometric

    Barometrics control the outlet pressure of a vented appliance which in turn controls the amount of combustion air that enters the burner.  Without controlling this pressure the amount of combustion air supplied to a burner is more or less random selection.  I learned from the very beginning that you must control both fuel and air, and yet the industry today still denies it.

    Drafthoods basically disconnect the appliance from the chimney and allow uncontrolled combustion air and venting.  If the chimney is not connected to the appliance then it is connected to the building which means the building pressures have a bigger influence on draft.  They were specifically invented to keep pilots from blowing out in the 30's.  Because there were no safety pilots back then it seemed like a good idea at the time.  All gas equipment originally came with barometrics.

    With a barometric you now know how much air is being delivered to the burner.  With a combustion analyzer you can now maximize safety and efficiency of the equipment.  Since 1980 when I started to teach contractors how to install them and adjust them and tune equipment we have seen saving of 5% to 15%.  Also rusting, corrosion, condensation issures seemed to disappear.  Whenever there is rust there is a venting problem 100% of the time..  If there is a drafthood there is no control of venting, combustion air or safety.  Barometrics with safety spill switches provide maximum safety, minimum wear and tear on equipment and the possiblility of maximizing efficiency.

    Barometrics when retrofitted on most gas appliances are set by combustion analysis not a draft reading. 

    In my class manuals the biggest print we use states "If you can't control the flue, you can't control the appliance!!"
  • ChrisJ
    ChrisJ Member Posts: 11,980
    edited October 2011
    I would

    also be interested.  I have a Weil-Mclain EG series boiler which is a lot like crash's with a damper and EI pilot.  Do you have to some how seal the vent hood and is this considered against code?   As in if the system is set up perfectly using a barometric damper and for some reason there is a problem will insurance automatically blame the modified boiler?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Barometrics

    I have been showing contractors how to do this since 1980.  Tens of thousands of residential and commercial furnaces, water heaters, boilers and other drafthood appliances have been modified and supervised by me directly.  Possibly 10 times that or more have been done by my students.  Code does not apply to service work or any type of retrofit.  Adding flue dampers is not approved by code or manufacturers but it has been done for years. 

    I believe in preventing things from happening and adding additional safety versus waiting until after an incident occurs.  To date, no incidents caused by this modification but ten of thousands have been prevented,
  • ChrisJ
    ChrisJ Member Posts: 11,980
    Fair enough

    How do we learn how to do it or find someone that can do it for us?



    I'm in central NJ and am willing to learn anything and everything.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Tim McElwain
    Tim McElwain Member Posts: 4,481
    Chris J

    you can find a seminar that Jim Davis may be doing in your area as one choice.Go to www.nationalcomfortinstitute.com for schedule. Or maybe Jim will chime in here and let you know when he will be in your area. 



    You could also come to my seminars (5 days)  in Rhode Island and we show how to do this or attend my three day "Testing Design Gas Equipment" and we actually go out and work on equipment in the field.
  • Tim McElwain
    Tim McElwain Member Posts: 4,481
    Crash are you a home owner

    or a technician?



    As a homeowner this is not something you should undertake.



    I would also suggest that who ever you have do this has attended Jim's or my classes so that they know what is involved with this process. This is not something to be undertaken by a novice. You have to know what you are doing.



    This forum is not conducive to teaching you how to do this. If you want further information e-mail me at [email protected] or call 401-437-0557.
  • crash2009
    crash2009 Member Posts: 1,484
    Well, thats a relief

      Nobody told me I was "nuts".  I was just thinking about Steamheads post-mortems of atmospherics and how he says they are always rotted out at the waterline on the fresh water side of the boiler.  Would a barometric damper reduce that problem?  Also he mentions frequently a lot of boilers that have too much air.  I don't have any testing equiptment, but I do know one thing, and that is, that when my boiler is running, there is enough air coming through the fresh air intake to blow your hat off.  I suppose I could lock the neighbors cat in the boiler room and see if it gets sucked up the chimney. 



    But seriously though Jim, How would I look into getting something like this done.  Do you have any students in the Detroit area?  I called our boiler guy today, he has some experience with barometrics, and I know this other guy with an analyzer.  Between the 3 of us we might have half a chance of getting it right.  I don't like those odds.  Rather hire someone that knows what they are doing.
  • crash2009
    crash2009 Member Posts: 1,484
    Tim

    I really do understand why I should not attempt this project myself.  I would rather hire someone that knows what they are doing.  Do you have any graduates in the Detroit area?
  • crash2009
    crash2009 Member Posts: 1,484
    Thank-you

     for the advice over the phone Tim.  I did go to  www.nationalcomfortinstitute.com  punched in my zip code, and found a local company, Koch and White Heating.  I will call them tomorrow and inquire about a maintenance contract.  With your help, that step was not as painful as I thought. 
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Barometric/Combustion Training

    There is a class scheduled for Northern NJ Nov 14,15,16.  It covers complete CO and Combustion Diagnostics and explains the dangers of drafthoods and why I was told many years ago by a test lab that they are possibly one of the most dangerous devices ever invented.

    Garno Brothers is also an excellent choice in the Detroit area.  They were in a story on the front page of Air Conditioning News a few years ago for saving a families life and retrofitting a boiler with a barometric.  The manufacturers was called by the editor of the story to see if they approved this retrofit.  Unofficially they stated that as long as the contractor knows what he is doing they have no problem with it.  Of course they could have said know and then the lawsuit against them would have begun for supplying a boiler with no safety cutouts in the flue. (not a requirement, just the right thing to do).
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Where did it begin-barometric retrofits?

    Back in the late 70's and early 80's there was an energy crunch, natural gas freeze etc.  The government was giving 50% tax rebates on all energy devices installed, from setback thermostats, spark ignition systems, flue dampers, reset controls, equipment upgrades etc., etc.  Sound familiar?

    Anyway I was introduced to a product in 1979 called a Thermostack.  This was a hot water coil that was installed in the flue of boiler and water heaters.  Some of you may be familiar with another brand called Cain.  There were installed mostly on commercial equipment that was over 400,000 btus.  I would do a combustion analysis and plug it in to a Texas Instruments calculated with magnetic strip programming and figure out the size of coil required and the potential payback.  The coil recover additional temperature from the flue gasses and return them back to the equipment.   Basically an extended heat exchanger.  If the flue gas temperature was 500 degrees the coil would be size and adjusted to lower this to 300 degrees.  This would represent a 40% recovery of the flue loss.  If the flue loss was 25% then there was a 10% savings.

    However, installing this coil above an open drafthood didn't work because drafthoods draw in dilution air and the temperature above most of them is less than 300 degrees.  Therefore it was standard procedure to block or remove the drafthood and replace it with a barometric above the coil.  No manufacturer of equipment approved this modification but were forced to accept it because the whole procedure was AGA, UL certified. 

    It was during a test in 1980 that I first discovered deteriating combustion.  Using a digital combustion analyzer that my wholesale house was selling(well,just me) I had left probe in the outlet of the boiler for more than 20 minutes with the analyzer running,  For the first 20 minutes, no CO was measured and then it jumped to over 5000ppm.  I didn't have a clue at the time why but I certainly started paying attention during testing like never before.  It wasn't long when I discovered that drafthoods were not designed or tested to handle high draft, just low draft.  In more than 50% of the equipment I tested after that I discovered the drafthood was pulling in too much excess dilution air and blocking the escape of flue gasses.  However, when a barometric and water coil were installed, the problem ceased.  What about all the equipment that had the same problem but couldn't use the water coil.  Why couldn't we just install the barometric to make it safe?  What we discovered is not only did it make equipment safe, it eliminated all rusting and sooting, and because we now had total control of combustion air to the burner we could adjust the fuel to match the air more closely.  This was providing 4% tp 12% saving all by itself and was a fairly inexpensive installation versus it plus the water coil.  The rest is history. 

    Obviously those that don't understand combustion, venting, combustion air don't understand this concept.  Again every installation included extra safety spill switches that the equipment never had. 

    I am totally mind boggled knowing that to this day GAMA, AHRI absoluting do not recommend adding safety switches to equipment that don't have them. According to an article in Air Conditioning News, equipment is safe enough and it shouldn't be our concern.

    Even though a barometric installed wrong is safer than a drafthood installed correctly, this should never be done by anyone without the proper training or a combustion analyzer.
  • ChrisJ
    ChrisJ Member Posts: 11,980
    edited October 2011
    I'm not trying to hijack the thread

    but I have a question which has had me confused for some time.



    Tim, Jim,

    What is the difference between a 40K btu water heater and a kitchen gas range with an oven?  The gas stove and oven burns quite a bit more gas if you have the oven and all burners lit and yet NO venting is really required?  I have to assume the stove products plenty of CO and yet it is considered safe in my kitchen.

    Sure, most have an exhaust fan but you are not required to have one, nor must you run it.



    Why is it safe for a 40-60K btu gas stove to not have any vent, yet a 40K btu gas water heater is considered a doomsday machine if it is not vented 100% perfectly?  I consider both to be intermittent use devices 99% of the time.  Is there a crucial thing I am not realizing?



    I"m asking this not because I doubt anyone, I'm asking it because I don't understand and want to.



    -
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • crash2009
    crash2009 Member Posts: 1,484
    Burning lean

    I can do a comparison shop with Gamo Brothers and Koch and White, (Koch and White was the only one listed in Ann Arbor 48103) I do prefer to deal with smaller company's.  I don't know a lot about this, but I do agree on one thing and that is that the draft hood/electric damper is not the most favorable choice for me.  The damper is either open or closed and I can't understand how that could even be adjusted to the changing conditions of the outside atmosphere. 



    If I may compare the bottom of my boiler sections to the spark plug in an internal combustion engine, the white discoloration suggests to me that it is burning too lean.  I know you can't tell just by looking, the gasses must be analyzed.  But from my untrained eye, that's what it looks like.



    On the other statement you made about less rusting and corrosion on the equipment, I think I can understand that.  When my boiler is steaming, it's pulling air directly from outside.  So we are burning (most of the time) wet air.  This wet air has to evaporate somewhere, and that would be somewhere between the flame and the flue.  Most likely it's evaporated on the boiler, which causes the rust you say is caused by the draft hood.  While the baro would still be pulling air from the same room, the air would be slightly less wet, but the big part is that it is pulled in after the flame and not before. 
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    oven vs water heater

    You could have included unvented gas logs with this also.  I could give the old standard answer which is; because water heaters are supposed to be vented and ovens are not.  Doesn't that give you a feel good feeling all over???

    Several things come into play and I can think of 4:

    1.  Location they are installed

    2. Hours of operation

    3. Fuel/air mixture settings

    4. Height of burner from floor

    1.  A water heater can be installed in a confined space, closet, basement etc.  This would have a large affect on how much combustion air is available.  Ovens are usually in unconfined spaces(kitchen) which communicate with most of the rooms on the same floor for air.

    2.  A water heater runs several hours a day 365 days a year or can.  An oven may be used a dozen times a year for holidays and special occassions, unless of course your Italian grandmother is living with you and then the oven may run more than the water heater. 

    3. An oven burner is set for a lean fuel/air mixture and usually has 12% to 14% excess oxygen in the flue gas.  A water heater is set richer and operates at the minimum excess oxygen of 4% to 6%.  What this means is that there is very little room on a water heater for any deficieny of air or the CO will go off the scale.

    Even though an oven burner is set lean, the flame hit directly against a spreader plate and must be adjusted properly for minimum CO to be produced.

    4.  The main by-product of combustion is CO2.  CO2 is heavier than air and falls quickly to the floor.  Any air on the floor will be displaced by the CO2 if there is no other place for it to go.  A water heater burner sits within a couple of inches of the floor, whereas an oven burner sit 18" to 24" above the floor.  Most oven are above grade.  Obviously the oven vents 100% of its CO2 into the space but it has many places to leak out of the room and never can build up to the burner level.  A water heater however with the low burner can run out of air very quickly if there is spillage.  Even if a furnace is spilling in a room with the water heater the water heater is the first appliance to become dangerous.

    These are some of the major reasons that separate a vented water heater from and unvented oven.
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Moisture

    White is not CO/Combustion Certified so they don't know how to do barometrics while Kotz can.  There is also a Lakeside Heating in Brighton.

    White flaking and corrosion are caused by flue gasses condensing before they are able to exit the equipment.  The majority of moisture is created by the hydrogen in the fuel not the humidity in the air.  This is acidic moisture with a PH around 4.

    Failure to remove this moisture which initially is in a vapor state, causes the corrosion and white powder dusting.  Attaching the flue to the appliance and controlling venting with a barometric assures these things won't occur.
  • ChrisJ
    ChrisJ Member Posts: 11,980
    Thank you

    for the detailed response Jim!  I understand now and appreciate you taking the time to respond.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Your Welcome

    Thanks for asking in the first place.  I am sure there are many others that have considered the same question but might have felt everyone knows the answer so they were afraid to ask. 

    Might also answer the question of whether opening a window when you have an unvented fireplace will provide adequate combustion air?  No!! Window is too high.  CO2 in on the floor.
  • Steamhead
    Steamhead Member Posts: 14,858
    Stoves can produce lots of CO

    the very first thing I tested when I got my first analyzer was my kitchen stove. The house, and the stove, had been my grandmother's, and I remember her buying that stove in the late 1960s- she was so proud of her new Norge! The oven was producing 1100 PPM of CO- now I know why I always got a warm fuzzy feeling when she cooked. I got it down to 20 PPM or so.



    Since then, I've tested a lot of stoves, and almost all of them have produced high CO- most of them from the ovens. And especially with tighter houses, we can't afford this.



    Test Everything!
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • ChrisJ
    ChrisJ Member Posts: 11,980
    testing

    Is there a somewhat affordable tester that homeowners could buy to test with?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • crash2009
    crash2009 Member Posts: 1,484
    Set for November 8

    Thank-you Jim,



    I just got off the phone with Lakeside in Brighton.  The receptionist read me the the checkpoint list of what they do for a yearly service.  I set an appointment for  them to come over and do the service.  I asked the receptionist for a quote on the barometric.  It was re-assuring to speak with someone around here that knew what that was.  I'll probably get the barometric installed at the same time.



    Steamhead, what is your input on this?  Would a barometric damper have helped any of those rotted atmospherics you have replaced?
  • Steamhead
    Steamhead Member Posts: 14,858
    No

    from what I can tell, they rotted out from excessive make-up water. We just replaced another one that rotted out for the same reason- watch for pics in the Strictly Steam area. 
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Excess Make-up Water?

    I can understand how excess make-up water could rot the water side of a boiler but how would that rust out the fire side??
  • crash2009
    crash2009 Member Posts: 1,484
    edited October 2011
    Water heater needs one too

    The tech says if I want a barometric on the boiler, he must install one on the water heater.  I did wonder if that would be necessary.  Why is it necessary?  I suppose anything sharing that chimney would need one too. 



    Just thought of something, if the water heater needs a baro because it shares the chimney with the boiler, then it will need a blocked flue switch and something to shut off the gas to the water heater.
  • Steamhead
    Steamhead Member Posts: 14,858
    Simple

    the rot starts on the water side and works its way thru the iron until it gets to the fire side.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • lchmb
    lchmb Member Posts: 2,997
    edited October 2011
    ok...

    So the idea behind the damper is to create a more positive controlled draft over all while at the same time adding safeties to the system Jim?
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Barometric on water heater

    It is always a better choice to have a barometric on all appliances that share the same flue and in some cases share the same room.  It is what I recommend in class to guarantee the safety of all equipment.  Most water heaters have no safety to shut them down if they start spilling.  I would rather be 100% safe than 50% safe.  Also many water heaters build up rust inside that cakes up in the heat exchanger because of poor venting.  I know of cases where this rust has broken loose and plugged the inside of the heat exchanger and poisoned people.  A good contractor will always recommend both because he cares about your safety.
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,195
    I agree with Henry here

    I use barometric dampers only on power burners.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Draft control & safety

    Draft controls combustion air to the burner.   We regulate fuel, but without a barometric there is no regulation of combustion air, just hit or miss.  I find it hard to believe in these days and times people still don't understand that you must regulate both. 

    Safety is certainly a big concern.  How many times has a birds nest or squirrels nest been blame for a CO poisoning or death, when in fact it was equipment with no safties on it to shut it down.

    Drasfthoods were invented to keep pilots from blowing out when there were no safety pilots.  Those days are long gone and so should drafthoods.  I was told more than once by an engineers from certifiying labs that drafthoods are the single most dangerous device ever invented.
  • lchmb
    lchmb Member Posts: 2,997
    boy

    I'm getting a long list made for training idea's for next year already. 
  • crash2009
    crash2009 Member Posts: 1,484
    Pilot upgrade?

    Historicly, it appears the barometric was tossed in favor of the draft hood because the pilot wouldn't stay lit, and they didn't have a safety to shut off the gas valve.  I think I have the kind of pilot that glows cherry red, and if the pilot is not burning, the gas valve will not allow the gas.  After I install the barometric, will my pilot be blowing out all the time?  Will I need to upgrade the gas valve or pilot? 
  • Tim McElwain
    Tim McElwain Member Posts: 4,481
    edited October 2011
    I find that

    most folks until they have been educated and also see the results are concerned about this changing of venting application changing the design of the equipment What if the design is flawed?. The gas company I worked for had done some of this in the 1970's and early 1980's on commercial boilers that had problems simply due to the use of draft hoods. We could not keep the boilers operating without nuisance shut down with the draft hoods. Barometrics solved the problem. Those jobs are still running today.





    We would however not try this on residential applications until the AGA/Field controls reports came out in the 1990's. Myself and another instructor along with one of our engineers convinced my boss that this might be a way to solve some problems with certain jobs. We had several jobs with "curtain effect" problems and when the draft hoods were removed and barometrics installed along with spill switches and a vent cap we saw the problems disappear. This convinced us that this would be an effective way to solve venting problems. We did not however go out and start changing every system. Being a gas utility they still felt that they would not want to go that far.





    This is not some radical crazy bunch of people out in the field doing things just for the sake of doing it. These are proved procedures done by well trained persons who understand combustion. Most people in the trades that come through my center do not really understand combustion and many times due to ignorance leave dangerous situations in customers homes. You must be trained to learn how to test and then test. If you do not test you do not know.





    Every gas appliance vented into a chimney or any other kind of vent should have spill switches in place. It is the only real protection we have as related to poor combustion conditions.The manual reset will insure a service call that is why we use them and not one that resets automatically. Do not show the homeowner the reset as we do not want them resetting before testing the equipment for safe combustion. Oil has the Cad cell which is reactive to poor combustion and will not allow the burner to fire. With gas there is no visual detection system on residential equipment. We do have Ultra-violet detectors on commercial and industrial equipment. UV is just to expensive for residential use.





    Yes even water heaters should have blocked vent switches (spill switches). I like to see two one on each side to give full protection no matter which way the spillage goes. Things such as downdraft, back-draft, negative building pressure, blocked flue all cause spillage at the draft hood or barometric.





    Also while we are addressing this subject when installing a barometric on the heating equipment to replace the draft hood it only makes good sense to also change over all appliances into that flue. We have a lot of two family and three family situations with three boilers or furnaces and three water heaters. If you are going to do one do them all.





    I have a customer (my old landlord where my training center was located before moving to my present location)) that we changed over all the equipment to barometrics including three unit heaters inside the upstairs stores. The landlord pays the gas bill and over the years has reported a drop in his gas usage equal to 30%. This is calculated by his accountant so it is pretty reliable.
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,195
    If Tim says it can help I deffer to him

    I will be researching this more. The old man's voice is still loud in my ear about changing factory equipment. Tim knows way more than me on gas combustion.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
  • Henry
    Henry Member Posts: 988
    AHJ

    In Canada you are not permited to perform this type of modification to a gas appliance. You would need an exemption from the Authority Having Jurisdiction. We have discussed this in sub-committee meetings. I would as an expert witness in an insurance or court case lay blame to the person who would modify a certified appliance, if there was an incident. Barometric dampers are great on commercial equipment, specialy with tall chimneys. But, the manufacturer in his certified instruction manual must sign off on a barometric.
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    barometric retrofits

    It is a shame that both the US and Canada are still following standards that were at best marginal for the 1930's and 1940's.  Somehow technology has escaped the HVAC industry when it comes to testing and validating performance.

    A family of 3 was just killed this past week in Pennsylvania from carbon monoxide.  It is being blamed on a blocked flue.  No mention that the appliance that was operating had no safeties on it to shut it off in case this happened.  If this appliance had been modified with and barometric and a spill switch those people would still be alive.  That is at least half a dozen reported poisonings caused this fall by blocked flues already and no safeties on drafthood appliances.  In fact I would estimate about 98% of all CO poisonings from furnaces, water heaters and boilers are equipment with drafthoods..

    If one would check the equipment recall list for the past ten years you would find  almost 50% of the equipment recalled had drafthoods.

    If the rules say we are not allowed to make equipment safe then the equipment needs to be removed and replaced with something that is,  Unfortunately we are still selling water heaters and boilers that are not fail safe.  Boilers a little better, water heaters worse than ever if they are tank types.

    Is there really a code or standard that dictates what we can or can't do on a service call? 

    My standard is stay alive even if it means you will be cold and dirty.

    The industry standard is make sure you are warm and clean when you die.
  • Henry
    Henry Member Posts: 988
    Safety Code NFPA54 prevents one from changing a draft hood

    All new boilers with draft hoods have spill switches. All new gas hot water tanks have fusible spill switches ie, you have to change the tank if the spill switch works!

    In NFPA54, 1.4 allows you to make changes IF, the AHJ signs off on it. Otherwise, you are liable! Please also check 3.3.33 about draft hoods and 11.6!



    12.13.1 etc clearly spell out the need of a draft hood. 12.13.3 Specifies that the draft control device must be part of the appliance or supplied by the appliance manufacturer. A new adition to the 2009 code is 12.13.4 for controlled chimney draft and "ajusted accordance with the manufacturers' instruction" ie the applaince manufacturer.

    In effect, you are NOT allowed to retrofit a barometric instead of a draft hood. Please read your code! The only time you may do this is, with AHJ signing off on it!
  • Tim McElwain
    Tim McElwain Member Posts: 4,481
    No you do not

    have to change your pilot or gas valve and if anything the pilot and safety system will be more reliable and less likely to be reactive to drafting issues.



    By the way if your pilot is glowing "cherry red" with a thermocouple it needs to be adjusted to a dull red this will increase the life of the thermocouple.
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    NFPA54

    The first thing you read in NFPA54 is that nothing contained within it has been tested, evaluated or verified for accuracy or soundness of judgement.  It goes on to say:

    Anyone using this document should rely on his or her own judgement or as appropriate seek the advice of a competent professional.

    Who is a competent professional??  You or someone else??  Who has the most hands-on experience actually performing the work versus just reading a book about it?

    I think you meant 3.3.32:

    A drafthood is a non-adjustable device (that just what we need to address the infinite amount pressure variations in the field) that is designed to provide for the ready escape of flue gasses in the event of no draft, backdraft or stoppage beyond the drafthood.  (Otherwise we would snuff the flame an inconvience our customer).Also it neutralizes the draft of the chimney so it will pull no flue gasses from the appliance as 11.6 proves

    And how about 11.6 - ain't that a laugher.

    Hold a match flame next to the drafthood to make sure the vent gasses are going up the chimney.  The only thing that proves is going up the chimney is room air and that test may verifies the flue isn't plugged.  (1930's technology) The more the flame is sucked in the less flue gasses are actually going up the flue.

    12.13.1  I show this one in every class

    Vented gas appliances shall be installed with drafthoods.

    Exceptions: appliances requiring chimney draft for operation???? (Wait a minute it doesn't mention safe operation does it-never mind.  Don't want to make it safe)

    12.13.3 Only covers a barometric when it is supplied by the manufacturer not when it is field supplied.

    12.13.4 Applionces requiring controlled chimney draft shall be permitted to be equipped with listed double-acting barometric and installed and adjusted according to manufacturers instruction.(that would be the manufacturer of the barometric). You did overlook 12.16

    12.16 Any device that retards the flow of vent gasses shall not be installed in a vent connector, chimney or vent. (that is the definition of a drafthood?)

    I do believe the Code addresses new installations only!  Beside being written by persons that have never worked in the field, they are enforced by persons with even less knowledge.  Once again in the beginning of the book it states to seek the advice of a competent professional and I would hope you could look in a mirror and find one.

    If anything scares me and makes me worry about liability it is NFPA54.

    Look for my book soon on how to perform a proper autopsy.  Hey I watch NCIS, CSI and Body of Proof and a few others.  That should make me competent!
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    fusable links

    Also the fusible links on new water heaters is to check for the intake screen being blocked, not the flue.  I have already seen blocked flues on them and they didn't trip.
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