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

oldradiator

hi all, first time homeowner approaching 1-year in.

about 6 months ago my gas company came over after we called concerning a smell of natural gas in the basement. while they noticed a few leaks, they also noticed CO coming from the boiler and shut it down ("red tagged" it).

since then i've had no less than 5 professionals in here with wildlying varying opinions and diagnoses:

1. master plumber who also recongized the CO leak using a CO monitor and then never responded to follow up calls for service.
2. master plumber who didn't have a CO monitor and only opened the vent and lit a match to see if it was clean/drawing and then said to just turn it on and forget about it
3. master plumber who essentially said the same thing as #2
4. HVAC professional who said he couldn't start the boiler, "hot wired" it to start it up and then diagnosed it with a cracked heat exchanger and sent me a quote ($$$$) to replace it.
5. heating professional that said there's no cracked heat exchanger but there were some old components that could be replaced (i.e. not enough pressure, remove the Flo Control, etc.) and i could use a chimeny clean.

after the 3rd service call I called my gas company back to confirm it was safe to fire back up. again, they found very high levels of CO and a very small gas leak down by the burners.

now i'm stuck. i don't want to keep paying $$$ for advice but i also don't want to break down and spend $$,$$$ if it's truly a fixable/non-issue.

where do i even go from here? why is it so hard to get GOOD, RELIABLE and TRUSTHWORTHY advice?

i'm in Westchester County, NY.

thanks all!

STEVEusaPA

Your venting is incorrect and could be the cause of your CO problem. I'd find someone from here from your area, who understands combustion, has an analyzer and knows how to use it to diagnose problems.

Jamie Hall

I presume that one of those photos is of the cleanout door opening into the base of the chimney? At the very least you need a chimney sweep to come and verify that the chimney is clear and safe to use -- and put the cleanout door back on.

Then may I remind you that CO -- carbon monoxide -- is odourless and lethal? The boiler has been diagnosed with high CO levels in the house and a gas leak. It is unsafe to use, and was -- quite properly -- red tagged.

There are, however, a number of possible reasons for a CO leak. A cracked heat exchanger is one, but there are several others. What is needed at this point is a heating professional -- likely not a plumber, but they might be one on the side -- to come and diagnose the problem. It's not that hard to do, but you do need someone who actually knows what they are doing. Your number 4 may be the best bet, but you could ask him how he made that cracked heat exchanger diagnosis. What did he see to make him suspect that?

Your number 5 is quite correct in noticing some rather dubious old components, and it is possible that his diagnosis of the CO problem is correct -- a blocked or partially blocked chimney. But that is easily confirmed by a draught test.

pecmsg

Find a contractor trained by the National Comfort Institute in CO 
https://www.myhomecomfort.org/find-a-contractor/

oldradiator

Jamie Hall said:

I presume that one of those photos is of the cleanout door opening into the base of the chimney? At the very least you need a chimney sweep to come and verify that the chimney is clear and safe to use -- and put the cleanout door back on.

Then may I remind you that CO -- carbon monoxide -- is odourless and lethal? The boiler has been diagnosed with high CO levels in the house and a gas leak. It is unsafe to use, and was -- quite properly -- red tagged.

There are, however, a number of possible reasons for a CO leak. A cracked heat exchanger is one, but there are several others. What is needed at this point is a heating professional -- likely not a plumber, but they might be one on the side -- to come and diagnose the problem. It's not that hard to do, but you do need someone who actually knows what they are doing. Your number 4 may be the best bet, but you could ask him how he made that cracked heat exchanger diagnosis. What did he see to make him suspect that?

Your number 5 is quite correct in noticing some rather dubious old components, and it is possible that his diagnosis of the CO problem is correct -- a blocked or partially blocked chimney. But that is easily confirmed by a draught test.

thanks. this was the verbatem diagnosis from #4:

Your boiler have a cracked heat exchanger.
Initially I had it to bypass the rollout flame sensor to get the boiler to fire and with my flu analyzer I’ll be able to determine that your heat exchanger is cracked with over 3000 ppm’s of CO2

SlamDunk

What would a cracked heat exchanger look like on a water boiler? A wet basement floor? Steam coming out the chimney?

I would focus on finding someone who knows how to troubleshoot and test combustion on gas burners.

A plugged chimney is fairly easy to check. Stick a dial thermometer in the stack while it is running. It should run in the upper 300's. 425 & up may indicate blockage-low draft. A combustion analyzer is a better tool. But, a thermometer works.

If flue is clogged, the heat builds up and CO backs up into basement. But, if you had a spill switch on that unit, it should open and prevent burner from firing until it is reset.

Also, double check that your automatic damper is opening fully. It is low hanging fruit that is real easy to check. Since you are new to this system, cant ignore the possibility a safety is jumpered. Not likely, but it does happen.

nicholas bonham-carter

A cracked “heat exchanger” should have water coming out-do you see any?
I also think the exhaust flue is incorrect, and the CO could be coming out the hot water heater, perhaps also because of a blocked chimney.
Can you use a mirror to look up the chimney to see if it is clear, in daylight, from the clean out?
Ask the wholesale houses to give you the names of people who know boilers-even retired ones. Such as F W Webb co: 1020 Mamaroneck Ave, Mamaroneck, NY 10543–NBC

oldradiator

nicholas bonham-carter said:

A cracked “heat exchanger” should have water coming out-do you see any?
I also think the exhaust flue is incorrect, and the CO could be coming out the hot water heater, perhaps also because of a blocked chimney.
Can you use a mirror to look up the chimney to see if it is clear, in daylight, from the clean out?
Ask the wholesale houses to give you the names of people who know boilers-even retired ones. Such as F W Webb co: 1020 Mamaroneck Ave, Mamaroneck, NY 10543–NBC

nope, no water that i can see. i don't think the chimney is blocked because one of the techs tested the water heater and found no CO.

i will call FW Webb!

JakeCK

Isn't there supposed to be a draft hood on this?

EBEBRATT-Ed

@old radiator

You do have one sort of serious issue that could be related. You notice the cracked concrete under the boiler? If I am not mistaken HB Smith requires that that boiler be set up on blocks to keep it away from the floor.

I will search for the install manual.

How do I know? Because I installed one wrong myself and had to fix that issue

In addition to the above you can try "find a contractor on this site"

Tinman

Like @SlamDunk said, the HX on that hot water boiler is made up of cast iron sections filled with water. If they were cracked, you’d have a water on the floor. 

I’d say it’s plugged up with soot and needs to be cleaned. And then you’ll need to find out why it’s sooted. Flame impingement? Gas pressure? Combustion air? The flame is rolling out because it’s looking for a place to burn. You don’t need to have someone trained by the National Comfort Institute, but it wouldn’t be a bad idea. The main thing is that they understand the combustion process, combustion analysis, and how to correct the problem safely. 

Jamie Hall

Right you all are. Somehow I shorted out... and if it's hot water, a cracked heat exchanger isn't the problem. So much for tech. number 4...

oldradiator

just as a follow up question; after the last tech left today i had the heat on for a few hours. family is now in the house (boiler is off). i have CO detectors on each floor of the house. theoretically, we should be OK?

HVACNUT

Did the tech do a combustion analysis and draft test, and leave the report with you?
Was the clean out door put on and sealed? That's where you lost draft. 
Got a canary?

oldradiator

HVACNUT said:

Did the tech do a combustion analysis and draft test, and leave the report with you?
Was the clean out door put on and sealed? That's where you lost draft. 
Got a canary?

so i don't know what either of those tests consists of. the last guy didn't do any "test' per say. he opened the clean out door and showed me how it was completely blocked up. he left it open when he left.

tech #1 had a combustion analyzer but all i saw him do was stick it in and wait until it read something
tech #2 lit a match under the flue and saw that it was drawing up so it deemed everything OK.

mattmia2

UL listed CO detectors aren't sensitive enough to let you know you have a problem until you have a deadly problem. You would need a CO monitor to determine if it was safe. From the looks of the soot on the front of that boiler, it won't be safe until someone cleans the boiler and fixes whatever caused it to soot up in the first place.

EBEBRATT-Ed

@oldradiator

I thought your question "Is the family safe in the house with the boiler shut off"

The answer is yes

oldradiator

side question: i assume if i don't get this fixed soon im in danger of my pipes freezing/bursting?

SlamDunk

It isnt that cold up there! You would need a few days with high temps below 32

HomerJSmith

It appears that there is a hole in the flue. That could be a CO test port and could be a source of CO.

I don't know Smith boilers, but isn't that supposed to have a draft hood? Or is it hidden behind the grate?

Is the vent damper operating correctly?

Re-gasket the flo check that's dripping.

If it is an exterior masonry chimney and it is cold outside, you could have flue gasses cooling in the chimney and falling back to the boiler.

oldradiator

i appreciate all the insights guys! a bunch more potential causes to add to my list (kidding...sort of). but, seriously, what a helpful forum.

i just hope i can find someone knowledgeable in my area. there's gotta be someone local on this forum.

hot_rod

Some of those boilers have integral draft hoods in the back. The installation manual would be useful. 

Draft or lack of can be based on temperature wind speed and direction. Usually a cold masonry chimney is when draft could be low or non existent. I would also get a chimney sweep, a licensed certified one if you can, to inspect.

Then the boiler should be inspected, probably cleaned. If it has had insufficient draft and flame roll out it is probably sooted

oldradiator

so it doesn't seem like many think it will need to be fully replaced. is that right or is there just not enough information to know?

SlamDunk

That is right. A sooted up boiler could be the problem. So could a clogged flue. The hard part is finding the right person with the right tools. But you know that already.

MikeL_2

Oldradiator,
              Your chimney may be too big ( 7 times rule) and need a liner, and, the boiler may be competing for combustion air with appliances that need / use make up air... ......

Steamhead

@oldradiator , go here to find a contractor worthy of the name:

https://heatinghelp.com/find-a-contractor/

oldradiator

Steamhead said:

@oldradiator , go here to find a contractor worthy of the name:

https://heatinghelp.com/find-a-contractor/

did that a few days ago. only one or two within 25 miles.

Steamhead

You might have to extend your range.

EBEBRATT-Ed

@oldradiator said

"did that a few days ago. only one or two within 25 miles."

Paying a little travel charge is better than the ham & eggers you have had so far.

That boiler does have an integral draft hood.

I can't find the manual since Smith has been taken over by Peerless.

@oldradiator can you post the boiler model #?

Zman

You probably either have a partially obstructed flue or a plugged-up heat exchanger.
Sometimes (with the boiler turned off) you can stick your phone in the draft hood on the back and take a picture (down) to the top of the heat exchanger.
You are looking for someone who can check the flue, clean the heat exchanger, and perform combustion analysis. I don't recommend you pay for any more opinions, call around and find someone who will agree to do those 3 things.
A boiler like that is pretty hard to destroy and pretty simple to work on.

Edit:
Inadequate combustion air due to incorrect space under the boiler could also cause your symptoms.

oldradiator

EBEBRATT-Ed said:

@oldradiator said "did that a few days ago. only one or two within 25 miles." Paying a little travel charge is better than the ham & eggers you have had so far. That boiler does have an integral draft hood. I can't find the manual since Smith has been taken over by Peerless. @oldradiator can you post the boiler model #?

EBEBRATT-Ed

@oldradiator

Here's the manual, maybe this will help. The older boilers had to be put on bricks for proper clerance. Yours does not

JohnNY

Since I started my consulting business 5 years ago, I get called to go to Westchester all the time. I've been saying for years it's an inexplicable dead spot of mechanical talent. Wildly inaccurate advice and prices for unnecessary work given by marginally qualified contractors is standard operation there. No idea why. It's a beautiful part of the world with magnificent homes.

oldradiator

JohnNY said:

Since I started my consulting business 5 years ago, I get called to go to Westchester all the time. I've been saying for years it's an inexplicable dead spot of mechanical talent. Wildly inaccurate advice and prices for unnecessary work given by marginally qualified contractors is standard operation there. No idea why. It's a beautiful part of the world with magnificent homes.

you got that right John

clammy

It looks from one of you’re picitures that there is some water under your boiler . The tech should have removed the burners and inspected the sections from below and removed part of the jacket and the flue collector to visually see the leak . A quick look at the pipe possible leads me to believe your system may be a high water content system and without a by pass or Thermidic valve would allow the boiler to operate below flue gas condensation temp causing possible blockages of flue passes and effecting the boilers draft . Has or did anyone check your boilers temps at any point to verify it operated within the proper temp range ? I often look at these things and ask myself why and as a wiser man stated once some times issues are not as simple as they seem and there may be other issues which where over looked and not really thought about , like the boiler operating below it flue gas dew point .running cast iron boilers at low temp on high water content system require some thinking not just attaching 2 pipes , this is what educated heating tech know and understand but being 99% say it not a issue years later it becomes a issue . It would seem to me that just about everyone was a-little lazy and did not remove the cover to locate and show the leak s as for what is the cause if they don’t have a answer I don t think I would entertain them doing a replacement . If your system has cast iron raditors and a steel pipe mains as in the pics you will need the new boiler installed using an better piping stragerty then what u have . Also I did not notice a expansion tank in your pictures on another note if it’s leaking at the section it’s possible the rods may need to be retighted to pull the section in . Also it always wise to put a boiler up on blocks and usually it should be completly solid under the boiler raising a boiler on blocks and not filling the area is not good it will increase the draft across the burners ,it usually states in the i and o manuals to install on a solid base there’s a reason for it but most never understand and prefer to pocket the money saved on blocks . Over the years I ve been witness to all kinds of stupidity most where usually caused by not looking completly at the system and or not understanding much about what they where looking at not really understanding Hydronics and different types of hydronic systems and there pluses and minuses and how to work around that to process the boiler usually all that thinking and thought isn’t free and does not lower the install price ,so let’s how the cheaper guys hence the results years later .
Now a days I don’t push the point I ll let some one else do it for cheaper and the HO will be happy they got a bargain until there’s issues then they can re do until they say uncle .
You need a professional in hydronics to take a look and pull it apart and verify the leak ,have a cert chimney guy take a look at your chimney and line it ,lining is cheaper then massive repairs and it will still need to be lined after repaired . Most hot water heating boiler last 20 to 30 years w proper setup maintance including bringing your system water up to snuf as to what the boiler manafactures requires and make sure there are no leaks anywhere .its a lot and it never cheap Peace and good luck clammy
My new and very old catch phase the sweeten of a cheaper price is always forgotten after the bitterness of poor quality

psb75

Important to determine where the wetness on the floor under the boiler is coming from. Choices: 1.) Boiler sections, 2.) boiler plumbing, or 3.) water heater? Clammy is right, that is some big, old, near-boiler plumbing indicating a high volume system. The larger (than a #30) hanging expansion tank would also indicate larger volume system. As Clammy opines: thermal condensation protection for the boiler? Not likely.

JUGHNE

My guess is that the draft diverter/hood is behind the front panel.

The discoloration on the upper portion of the grill indicates roll out of exhaust gases/blocked flue IMO.

Then with little draft from chimney because of clean out door open, being plugged or being a cold chimney exhaust gases could come out the draft diverter.

And possibly boiler passageways partially plugged.

The test hole drilled there should always be under a negative draft, if CO comes out of that just imagine what is coming out of the diverter hood just underneath it.

captainco

The hole that is drilled in the flue is the wrong place for a combustion test, but if there is high CO there you do have a big problem.
Flues can only be too small, never too big. Liners are only needed if the flue is falling apart but then that is caused by poor operation.
Does anyone realize the 7 times rule only applies if you have two pieces of equipment in the flue. If there is more the rule is out the window.

We can tell you all kinds of things that could be wrong, but unless a properly trained technician has the information it will not do much good.

It would be nice if you could find someone trained by the National Comfort Institute. They are the least gullible to stupid industry misinformation.

JohnNY

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

captainco

John,
I trained you in 2004. I think you thought I was nuts back then. What has been added to the class as far as diagnostics is way more detailed then is was then.
Like how to determine a flue is undersized or restricted using just a draft gauge.
Why using outdoor air connected directly to burners screws up combustion.

Why are manufacturers intentionally redesigning their equipment to discourage NCI recommendations?

One of my favorite quotes today is from Einstein - "Unthinkable respect for authority is the greatest enemy of truth." In other words, when you stop thinking and learning for yourself, your on a road to failure.

JakeCK

captainco said:

John, I trained you in 2004. I think you thought I was nuts back then. What has been added to the class as far as diagnostics is way more detailed then is was then. Like how to determine a flue is undersized or restricted using just a draft gauge. Why using outdoor air connected directly to burners screws up combustion. Why are manufacturers intentionally redesigning their equipment to discourage NCI recommendations? One of my favorite quotes today is from Einstein - "Unthinkable respect for authority is the greatest enemy of truth." In other words, when you stop thinking and learning for yourself, your on a road to failure.

I like that quote... so true.

How does outdoor air screw up combustion? Does this include high efficiency sealed boilers and furnaces, or are you talking about when outside air is piped to the room of a natural draft appliance?