Carbon Monoxide diagnostics

hmlj

New homeowner of a steam system. Had a reputable company out to inspect/service the boiler and walk me through some fundamentals prior to heating season. The technician was helpful, walked me through cleaning the burners, flushing the system, and it came time to run it. It fired without issue and he put his CO meter on top of the boiler. Over the next 10-15 minutes, the levels in the cellar started to rise. At 16 PPM he shut it off, closed the gas line, said the company policy wouldn't let him continue to run it, and deemed that I need a new boiler. Did I miss something during my trips to the thermostat? Is that all there is in terms of diagnostics? If there is CO present the boiler is faulty and must be replaced? What questions do I need to be asking the company when they call to discuss replacement? Thanks in advance for the advice.

hmlj

STEVEusaPA

What brand/model number?
You need a new tech.
Sure CO can be present, but to not find out why and call you boiler dead is unprofessional at best, a little shady at worse. One of the most 'reputable' companies in my area has a standing policy of selling people a new unit following the same kind of 'scenario' you were exposed to-the big CO scare-scam.
Don't get me wrong, I believe that there was CO present. Id like to know why. Too bad you didn't have a Go Pro running when you left the room.
Could be something simple. But the fact that he put the meter over the boiler and didn't do a combustion test is unprofessional, and sets off my spidey sense. Like he knew he was going to get CO numbers.
I'd call the supervisor, foreman, boss, owner--whoever and ask them to explain themselves about their business practices and exactly what is wrong with the boiler.
And a printout of the combustion results and the gas pressure would be nice.

NY_Rob

Take some photos of the boiler and the flue pipe and surrounds- post them here and perhaps one of the pros will spot something.

Could be serious, but could also be as simple as a blocked/dislodged/rotted flue pipe or something nesting in your chimney or a bad/blown over chimney cap, etc...
You don't condemn the boiler without investigating the source of the CO.. if it's a blocked chimney, even the new boiler will spew CO into the basement.

hmlj

Thank you both. First, I just want to say that it's not my intent to throw the tech under the bus. The company is well-respected, their installations appear to be really clean and professional; I specifically chose them because of that. I want to give them the benefit of the doubt until I have a good reason to otherwise. Like you both said, the matter-of-factness of the verdict is what caught me off guard as well.

He flagged the haphazardness of some of the plumbing, and the choice of copper for the near-boiler pipe, but everything seemed to check out on the boiler itself up until that point. Then boom, there was CO and he was packing up.

I was nearby for most of it, hoping to learn what I could, except when I went to the t-stat to shut down the unit. There just didn't appear to be much troubleshooting on his part and so I wondered if it really was that straightforward. Based on your responses, it doesn't sound like it is.

j a_2

Did it run up to steady state condition, prior to testing...Same as they tell you warm up your car prior to emissions testing? How much make up air do you require and how much do you have? How is the venting of exhaust, is it sized correctly? Do you have proper c o detectors installed and did they ever go off? Got any pictures of the beauty? It helps

j a_2

It can be the most beautifully piped boiler ever, but if it can't breathe in and exhaust out it can be a very bad day for someone

GW

Seems like an odd situation- yet i wasn't standing there for the whole event.

Did he make any attempts to correct the CO? Did he make sure the chimney was pulling a draft? Did he get down on his hands and knees to look at the burners? Did he try determining what burner (flue passage) was kicking out the CO? Did he say let me get my (so and so) person here that knows more about combustion than I do?

hmlj

Don't you hate when the OP never comes back to tell you the resolution? Me too, sorry about that. Last month was busy.

Based on your comments and my conversation with Weil-Mclain, I opened up the boiler panels to investigate. First thing I noticed was all the boiler putty sealing the collection hood to the top of the boiler was baked to dust with visible gaps. I removed the collection hood and vacuumed it clean. I didn't see anything obviously wrong (to me) with the boiler itself, other than being filthy. I called the service company back, explained my observations, and the owner and a tech came back out and cleaned the combustion chamber, resealed the collection hood, and did a draft and combustion analysis. No more CO. Phew.

Sidenote, he mentioned it was one of the worst installations he's ever seen, so I'll get some pictures of the overall setup posted soon.

Thanks everyone.

EBEBRATT-Ed

Thanks for the update. If the boiler is solid the piping can be fixed if it's causing problems. I have seen systems with less than ideal piping work ok. Time will tell...................

STEVEusaPA

Thanks for the update, also.
Glad you're problem was solved. Do you still think they are a 'reputable company'? What did the owner say about the first tech doing a half a$$ job and not inspecting/fixing the clean out box?

That's a pretty old Weil McClain. I wouldn't use furnace cement for that for the very reason you discovered-it dries out, cracks and crumbles. They make gaskets for that, which would hold up better/longer. Considering it's gas, most people don't get them serviced regularly, and don't open up the clean out to inspect.

A newer, better, properly sized, more efficient boiler (properly piped & installed) should be on your radar.

I would get a company that can show you a few examples of what they can do to bid on it.

mikeg2015

I thought that if draft was good, you should have a slight negative on the hood. My hood is 2 parts and completely open on the back half like a light-commercial boiler

How tall is that chimney? On an atmospheric boiler, I think there is supposed to be a hood above or below the vent damper not a sealed connection.But maybe it's not needed on this model boiler. It also helps lower the dewpoint and dilutes and increases velocity of the flue gases by mixing it with ambient air before going up the stack to reduce the risk of condensation.

hmlj

I would think that once it's drafting, the imperfect seal wouldn't matter that much; the collection hood itself is open on the underside. It may have been an extraordinarily dirty burn, it may not have been drafting well when the initial CO was observed prior to warming up, maybe both. I don't have a great explanation of what's going on, but I do have some peace of mind that it's ok to run.

STEVEusaPA

Sure but it's not drafting too well on start up, when CO is probably at its highest. And being that leaky cleanout is at the top of the heat exchanger, flue gas and heat are leaking out the top. Heat especially.

GW

anyone ever seen draft to high that the air velocity entering the hood blocked the flue gasses in the boiler, creating high CO? Text book Jim Davis stuff

JohnNY

GW said:

anyone ever seen draft to high that the air velocity entering the hood blocked the flue gasses in the boiler, creating high CO? Text book Jim Davis stuff

I think JD calls that an "eddie curtain"?

GW

I recall him saying air door or air curtain

icy78

A rectangular hood could give an air curtain effect and a round one could be producing eddy currents. High draft will do this. Also on a cold start, like what the tech saw(?) you could have spillage for a short time on first fire, particularly with that flue damper, keeping the flue air cool. You may need the hood blocked off, a barometric added and the the baro set per combustion analysis. It has to be determined first, however, if venting or combustion air is the issue. If you have enough draft, then combustion air is not the issue.
I'd say the tech may have known you'd get some spillage and tried to scare you into a new boiler.