Carbon Monoxide from Hydronic Boiler; 5 "Professionals", 5 Diagnoses...

oldradiator

Guys the wetness from the boiler was because the last tech opened a valve or something to check the pressure normally it’s totally dry. I took these photos right when he left.

oldradiator

JohnNY said:

I have been duly trained by The National Comfort Institute. Granted, I think it was 1995 or so, but hey, what’s changed in CO safety? 

@captainco do you happen to have a record of when I trained with you? 

-John Cataneo

What’s your travel to Westchester fee 

captainco

I think we all know that when molecules are warmer they move faster and expand. When molecules are cooler they move slower and contract. When molecules contract there is less surface and therefore less mixing with the fuel. A piece of equipment finely tuned in warmer weather could end up operating fuel rich in cold weather because the cold air isn't mixing with the fuel.

It is the same thing as when the fuel is cold such as an outside oil tank. That is the reason we don't recommend two lines systems because we take the warm oil that is inside and take it outside and replace it with cold air..

How much combustion air does a 200,000 btu condensing boiler require?

25 cubic feet per 1000 btus. or 5000 cubic feet per hour. But does it run an hour?
Maybe it runs at full input for 15 minutes. Not likely but possible on a cold startup. So that is 1250 cubic feet of air per cycle. How big a space is that? If I was using some type of fan to supply that air (fan-in-a-can, enforcer) I would need
1/4 cfm per 1000 btus or 50 cfm per minute of operation. And these numbers assume the room you are in is 100% air tight.

If that much combustion air is going to depressurize your house, you are going to have other problems.

Adding an open tee inside on the combustion air pipe does help temper the cold air and protects you from the pipe being plugged.

mattmia2

What about sealed combustion appliances where they take outside air all the time but sometimes it is 90f and other times it is 0f. The amount of air in a cubic foot of air is going to vary but the combustion controls control volume.

captainco

Think of it as the air is cold ice tea and you try to add sugar. Cold and hot don't mix well.

There might be more volume or weight of air in cold air but if the molecules are too close together they won't mix.

oldradiator

well...not the news i was hoping to hear. today's tech was awesome. told me to stay down there with him and explained/taught me along the way.

initially, he thought it just needed a good maintenance.







turns out, after further investigation...well - judge for yourself by the photos below

JakeCK

Looks like that Boiler has $*** the bed. Time to retire it and put it out to pasture. Looking forward to the pictures of the new install.

psb75

with just a little digging and a lot of knowledge--certitude!
A good thing.

psb75

Thanks for your diligent follow-up with report and photos!
That benefits everyone.

SlamDunk

That is unfortunate. But it looks soot free. Why the CO in the basement? Are you sure the flue is clear?

EBEBRATT-Ed

Could be water dripping on the flame cooling the gas and causing Co.

What @captainco mentioned above is correct.

IMHO many who stare at the combustion test instruments don't understand the flame will change as soon as you walk out the door. You should adjust the burner to keep the flame in a safe range....nor necessarly at the highest and best combustion test

I was told that with colder air the burner fan will deliver more air (thus a leaner fire) than when running in warmer weather but maybe this is wrong. The comments above about the temperature of the air may make the difference.

oldradiator

lol, guys, please don't tell me i didn't get a comprehensive enough analysis again...@slamdunk @EBEBRATT-Ed

captainco

It is true that colder air has more volume of air but considerably less surface area to nix with the fuel. If the air does not mix with the fuel we would see higher O2 readings in the flue gases but also higher CO because of lack of mixing. ASHRAE did do a study years ago stating cold air was not good for combustion. There was actually a statement in the study that said if the air was too cold it would get stuck in the pipe. I thought myself does that mean it would get stuck in your nose?

If you ever dealt with an industry that fuel was it major expense, you find out they preheated their combustion air and could operate at lower O2 ranges like 1% to 2%.

We have to remember most of the things we are told to do are based on opinion rather than actual field verification. Sometimes reading studies and so called results are funnier than the Sunday funnies.

When tuning up equipment it is important to evaluate multiple conditions rather than just one. I tell students to adjust equipment to determine where it will go bad and then build in extra safety to compensate for environmental conditions.

In my 40 plus years of combustion testing equipment from 4000 btus to 50,000,000 btus and higher I had to rely 100% on what I experienced rather than thinking I was smart.

After all these years I am still searching for some type of technical data that supports the crazy things I have discovered in the field. At this point I still have to answer the question "Why does that happen" with because it can, Murphy;s Law.

SlamDunk

oldradiator said:

lol, guys, please don't tell me i didn't get a comprehensive enough analysis again...@slamdunk @EBEBRATT-Ed

No, that's not what I am saying at all. I don't have all the answers. Your original post was a problem with high CO. Your last post was a rusted through boiler. You have to deal with that. Yes, you have a leak but it is very small. Seeping. I don't understand how that would cause high CO. I just fell into the ignorant territory again. Don't worry though. I find my self here often.

Steamhead

captainco said:

I think we all know that when molecules are warmer they move faster and expand. When molecules are cooler they move slower and contract. When molecules contract there is less surface and therefore less mixing with the fuel. A piece of equipment finely tuned in warmer weather could end up operating fuel rich in cold weather because the cold air isn't mixing with the fuel.

It is the same thing as when the fuel is cold such as an outside oil tank.

captainco said:

When tuning up equipment it is important to evaluate multiple conditions rather than just one. I tell students to adjust equipment to determine where it will go bad and then build in extra safety to compensate for environmental conditions.

This is basically the same thing I was taught, by @Tim McElwain , @Firedragon , @Alan R. Mercurio and others. So it *should* be common knowledge in our industry. Haven't made it to @captainco 's class yet though...... do you ever come to Baltimore?

Another thing worth noting is that when it gets very cold and gas demand is high, some gas utilities augment their gas supply with whatever they can get their hands on. This often raises the BTU content per cubic foot, which can make a unit run too rich. I really hate having to clean a sooted-up gas boiler- oil ones are bad enough, but at least they're made to be routinely opened and cleaned...................

oldradiator

What does everyone think of paying a $$$ service fee to one of the techs who misdiagnosed?

I just got the invoice.

captainco

Actually they used to add propane to the natural gas lines but now they changed to using liquefied natural gas from other countries. I would think with the new found supplies of gas that wouldn't be necessary. Also it is rare that the btus in gas is higher especially if the gas company charges by the cubic foot. If they charge by btus which is not the norm then it is possible.

We just did a class in Baltimore but I wasn't the one to do it. There was another class schedule in the area and that would of been teaching five days in a row and that pushes my limits. I am getting old. Not quite as old as Timmie but close. I am sure we will be back again and a good chance I will be teaching.

I don't like to mention our class schedule here because I am not trying to compete with the other great instructors here.

I am attaching one of our diagnostic sheets we use. There is a different one for most types of residential and commercial equipment, gas and oil. New ones are added as necessary and they are updated when necessary to make them easier. This is an older sheet that hasn't been updated. Some persons on here have these but not most of the newer ones. Only available in class. Sorry.

pecmsg

oldradiator said:

What does everyone think of paying a $$$ service fee to one of the techs who misdiagnosed?

I just got the invoice.

Don’t use them. 

Finding a good company is difficult. When you do take very good care of them!

Zman

oldradiator said:

What does everyone think of paying a $$$ service fee to one of the techs who misdiagnosed?

I just got the invoice.

I would call them and ask to talk to the owner or manager. State your case and see what they have to say. If they balk, you can always offer to "split the baby". If they send you to collections it will cost them about 50% anyway.

EBEBRATT-Ed

@Steamhead said

"Another thing worth noting is that when it gets very cold and gas demand is high, some gas utilities augment their gas supply with whatever they can get their hands on. This often raises the BTU content per cubic foot, which can make a unit run too rich. I really hate having to clean a sooted-up gas boiler- oil ones are bad enough, but at least they're made to be routinely opened and cleaned...................ead said,"

I only ran into this once (they call it shaving around here) in the same town with the same gas supplier on 2 different jobs. Power Flame commercial burners combination natural gas and oil. Constantly locking out. we must have made 8 trips there. It had a gas pilot for both fuels. We tried them on gas we tried them on oil and they still locked out so we knew it was something common to both fuels. The gas pilot. We checked and checked and couldn't make them fail.

Factory installed 6000 volt trans threw them in the trash and put on Webster 8500 volt which are no longer made.

That fixed both jobs never went back for that reason, and yes the electrodes were brand new and adjusted right. This was in the dead of winter found out the gas co was jambing propane into the natural to keep the pressure up.

My suspicion was first start in the morning when the boiler was cold the 6000 wouldn't light the propane. Once the boiler was hot it would

EBEBRATT-Ed

@captainco

Your explanation makes sense. Just like an oil burner nozzle sort of i reverse. Higher pressure out of the nozzle makes smaller oil droplets so they mix better with air

oldradiator

Here was the 4th techs propos

Zman

Discussing pricing is against the site rules.

PC7060

@oldradiator - it’s against site rules to post $$ values or quotes. Could you edit and remove?  It will save @Erin Holohan Haskell from having to go in to edit your post.  

Solid_Fuel_Man

@oldradiator

Personally I would highly recommend a properly sized condensing boiler. If i had to guess, your house is full of nice large cast iron radiators. The old piping near the boiler is large and indicates what was a gravity water system. Very large volume of water. 

This type of system is wonderfully suited to a condensing boiler and would operate very efficiently with your high volume system. 

Your old boiler was not made to operate at low temperatures and likely had flue gas condensation which rusted out the heat exchanger. 

Also, be sure the tech checked the condition of the chimney as has been said. I'd you opt for a condensing boiler, it will not use the chimney. It would vent with plastic pipe out a wall. 

Yoyr water heater would need to be replaced with either a power vent unit, or have an indirect water heater with the new boiler, or an electric/heat pump water heater. Your existing gas fired water heater most likely cannot be left as the sole appliance connected to the chimney if you go with a condensing boiler. 

mattmia2

Or put in a liner sized for the water heater.

oldradiator

Solid_Fuel_Man said:

@oldradiator

Personally I would highly recommend a properly sized condensing boiler. If i had to guess, your house is full of nice large cast iron radiators. The old piping near the boiler is large and indicates what was a gravity water system. Very large volume of water. 

This type of system is wonderfully suited to a condensing boiler and would operate very efficiently with your high volume system. 

Your old boiler was not made to operate at low temperatures and likely had flue gas condensation which rusted out the heat exchanger. 

Also, be sure the tech checked the condition of the chimney as has been said. I'd you opt for a condensing boiler, it will not use the chimney. It would vent with plastic pipe out a wall. 

Yoyr water heater would need to be replaced with either a power vent unit, or have an indirect water heater with the new boiler, or an electric/heat pump water heater. Your existing gas fired water heater most likely cannot be left as the sole appliance connected to the chimney if you go with a condensing boiler. 

thanks. the tech today actually thought that originally this was a steam system, hence the larger pipes.

replacing the boiler with a condensing boiler and changing the water heater sounds like a very expensive proposition. i'm already at $$$$ just for a regular gas boiler.

oh...and reattaching the previous tech's proposal:

GW

If you pop that front cover off, the draft hood is right there in front of you, as I recall. 

Cracked heat exchanger! Fantastic 

If the chimney is plugged or blocked, the spill switch should kill the burners, hard lockout

If the draft is too much, that could create some problems. But if the high CO is  happening right away, I bet 13 donuts it’s not the draft nor the chimney. But I’m just winging out ideas, everything needs to be looked at

as mentioned, I suspect or some sort between the sections. Not a fun job 

oldradiator

GW said:

If you pop that front cover off, the draft hood is right there in front of you, as I recall. 

Cracked heat exchanger! Fantastic 

If the chimney is plugged or blocked, the spill switch should kill the burners, hard lockout

If the draft is too much, that could create some problems. But if the high CO is  happening right away, I bet 13 donuts it’s not the draft nor the chimney. But I’m just winging out ideas, everything needs to be looked at

as mentioned, I suspect or some sort between the sections. Not a fun job 

check out the photos in post #28

Erin Holohan Haskell

PC7060 said:

@oldradiator - it’s against site rules to post $$ values or quotes. Could you edit and remove?  It will save @Erin Holohan Haskell from having to go in to edit your post.  

Thank you!

WMno57

Good morning @Erin Holohan Haskell. I'm an early riser, so I got to see the "forbidden" pricing for a little while. I'm guessing you punched in about 6:30 AM your local time. That's impressive! Maybe you got your work ethic from @DanHolohan. I'm a big fan of your site, and have learned a lot here the last three years.
Wishing you and your family a Merry Christmas, and a prosperous New Year.
@oldradiator, As a fellow homeowner I share your frustration. However, this site is Erin's, it's her house, and her house rules. Mrs. Oldradiator might have some house rules for you and your home (like keep her and the children warm). You have a big decision to make. My suggestions follow:
Forgot about a Mod-Con (Competent installation is required to get them to last half as long as a traditional lower efficiency cast iron boiler) As @JohnNY stated, and you have discovered, competent hydronic professionals are lacking in Westchester.
The price you posted was in the ballpark. Time is money. You could pay to send your family off to somewhere warm, drain your domestic water and heating pipes, and winterize the toilets. This would buy you time to get 1 or 2 more quotes for lower efficiency cast iron boilers. My hunch, is that all the quotes will all be in the same ballpark. It does need to be determined, WHAT CAUSED YOUR CURRENT BOILER TO DIE A PREMATURE DEATH, or it will happen again.
Get that chimney checked out.
Wishing you a warm holiday season in your home.

mattmia2

oldradiator said:

the tech today actually thought that originally this was a steam system, hence the larger pipes.

The large pipes are because it was once gravity circulation with the original boiler, it did not have a ciruclator. That isn't a great sign for the tech.

The leak in the boiler doesn't in itself explain why it is making CO or why it isn't going up the chimney. That corrosion around the bottom of the draft hood makes me suspicious that it never vented very well. Definitely should do the math on the chimney and the vent connectors and very likely you will have to line the chimney with the new boiler if it is natural draft.

I thought I mentioned it somewhere but not sure, you could put in a mod con and a liner sized for just the water heater.

Erin Holohan Haskell

WMno57 said:

Good morning @Erin Holohan Haskell. I'm an early riser, so I got to see the "forbidden" pricing for a little while. I'm guessing you punched in about 6:30 AM your local time. That's impressive! Maybe you got your work ethic from @DanHolohan. I'm a big fan of your site, and have learned a lot here the last three years.
Wishing you and your family a Merry Christmas, and a prosperous New Year.

Thanks, @WMno57. Yes, I did. Beautiful sunrise, coffee, and The Wall. Merry Christmas to you and your family as well!

oldradiator

Well if @JohnNY wants to take a trip up to Westchester that would be cool…lol

oldradiator

Oh man @mattmia2 I hope you’re right and maybe I got misdiagnosed again. This is ridiculous. The tech assured me the photos from his mini camera (pictured above) confirmed a cracked heat exchanger.

The last tech is blaming moisture and steam for the CO rolling out. He says the moisture and steam is due to a very small crack in heat exchanger.

mattmia2

You need a new boiler or at very least an expensive repair to that boiler. The caution is that there might be more going on with the CO and venting, others here will have a better idea about the tech's theory than I will.

EDIT:
I think I have an idea. Going back to the theory about the high mass converted gravity system and the lack of low return water temp protection, maybe the system is oversized to the point where it never really gets up to temp so the boiler is condensing a lot. That cold boiler will make it not draft well and the condensation will explain the rotted out boiler section. You need to make sure whoever replaces it understands what it means to put a modern boiler with a ciruclator on a gravity system.

delcrossv

mattmia2 said:

EDIT:
I think I have an idea. Going back to the theory about the high mass converted gravity system and the lack of low return water temp protection, maybe the system is oversized to the point where it never really gets up to temp so the boiler is condensing a lot. That cold boiler will make it not draft well and the condensation will explain the rotted out boiler section. You need to make sure whoever replaces it understands what it means to put a modern boiler with a ciruclator on a gravity system.

Just thinking out loud, but would a solution be to install a heat exchanger between the boiler and the heating loop? That way you could control circulation though the boiler so it stays above condensing temperature and the heating loop can run at whatever speed/ temperature it needs to for comfort (which is probably very low in comparison)..

mattmia2

There is a much simpler method, you just need a thermostatic or fixed bypass to circulate some of the hot supply water from the boiler back in to the boiler.

EBEBRATT-Ed

Yes a 3 way mixing valve with a good control and a temp sensor on the boiler return.

I do agree with the tech that any steam/water generated in the combustion area may chill the flame and cause Co. There is no doubt that could be possible

WMno57

I have a 1916 high volume gravity pipes and radiators system heated with a 70 year old cast iron boiler. No bypass or heat exchanger. I guess it has lived this long because it is warm start and standing pilot? Also a very inefficient boiler. Don't know if any of today's cast iron boilers could survive my no bypass setup without condensing.