CO issue with new gas furnace

[Mark325i]

First time poster from Long Island.

This past June I had my old oil burner system replaced with a Burnham ES2 gas boiler and hot water system. The furnace is in an unfinished work room in my basement. About two weeks ago at about 6am, the CO alarm went off in the finished part of the basement. I went into the furnace room and everything seemed to be running OK but the room was warmer than I remember it getting and it was damp. I later attributed the dampness to the laundry that was hung in there. I opened the window and called the installer. He came by and checked the draft and the settings on the system and everything seemed OK. The alarm had not gone off again, and I was not sure if it was beeping in the pattern that alerts to an actual detection of CO.

Forward to today, the alarm goes off again, same time. This time I notice that the beep pattern is signifying that it is detecting CO. I go into the furnace room and it is very warm and damp and there was no laundry hung up this time. The flue is open and drafting (I put a piece of smoldering paper near it and it drew in the smoke). I was thinking that maybe the CO alarm is faulty (and I am getting another today just to make sure) but the atmosphere in the room is what gives me pause.

Could the space the furnace is in be too confined? It is about 288 SF, and the furnace is 105,000 BTUs. Any and all thoughts would be appreciated. Thanks.

[Dad]

Moved from the General Forum

[beenthere]

Where does the combustion air come from?

[BaldLoonie]

You would need 650 sq ft with 8 foot ceilings. You are greatly shy on space and could be running out of combustion air. What does the boiler vent in? If a masonry chimney, needs an appropriately sized metal liner kit installed. Or could vent in double wall metal pipe through the roof.

[George2]

The dampness is from the exhaust gas that is not going up the chimney. The reason it vents properly when you check it is that the door to the room is open to the basement giving it some relief (combustion air).

I've seen where attic exhaust fans will reverse the furnace /water heater vents located in the basement! Imagine that!

[Joehvac25]

FYI high co levels will knock you out before you even know you have a problem, seen a man dead next to his boiler to prove it, be careful.

[jtrammel]

Please turn boiler of until you have a thorough inspection of boiler and flue/chimney. CO is extremely deadly. Google low level CO detectors and invest in one, they actually work as opposed to the ones sold at home improvement stores. Have a Qualified boiler technician do a combustion analysis and correct whatever is wrong. DO NOT OPERATE THE BOILER until the problem is corrected. It's better to be a little chilly than dead.

[George2]

FYI high co levels will knock you out before you even know you have a problem, seen a man dead next to his boiler to prove it, be careful.

I was called to a house to give a furnace estimate. They were to leave the door open because no one was going to be home. I went to the basement, saw all the soot on the front of the furnace, did my thing and got out of there. By the time I got into my car, I had a headache like I have never had before. I could not have been in the home more than 15 minutes. I do not know why it did not kill anyone. Remarkable. I called them and told them not to go back to the home. I never did hear from them again.

[martyinlincoln]

While I can't answer the question of why it's spilling CO without testing I will give some advice. When that store bought alarm goes off it means the CO levels have been high for hours. Walking into the boiler room at that point is NOT something you want to do. That's get out of the house time. Shut it off until a good HVAC tech trained in combustion analysis can fix the issue. It would be a good idea to go to the doc and get checked for CO in your blood.

[dsprice]

TURN IT OFF and get a combustion analysis today, right now! Stop reading this, you should be on the phone calling someone allready...

[Mark325i]

Hello, all. Thank you for the advice. To answer some of the questions: Currently, the combustion air comes from the basement/house. No outside air supply (for now). The furnace vents thru the existing chimney, which was lined with a metal sleeve. Combustion tests have been done, and they have been good, but they were done with the basement door open. The two times the CO alarm went off was on cold days when it was calling for heat and hot water. The unit has an outdoor resent control, so I am guessing that the flame was higher on the cold days to generate enough heat to heat the house and water, hence greater combustion air was needed.

The old furnace (an oil-fired unit) lived in the exact same area and environment for 40 years and the CO detector never, ever even beeped. Sine I posted this, I had the fire department come in and do a CO test and everything was fine and the fireman told me he thought the problem was running the unit with the door to the room closed. Right now, the door is open and the window near the unit is open. My contractor is coming back to install an outside air supply.

[dsprice]

I'm glad you and your family are safe.

Sent from my GT-P3113 using Tapatalk 2

[kdean1]

The fire department can test for the presence of CO. However they are NOT experts on combustion. What the fireman THINKS may be right, but I'd rather KNOW the source of the problem and resolve it. An HVAC contractor who has been trained in combustion analysis will not be guessing as the fireman did. Don't pin your hopes and the lives of your family members on someone's guess.

[gravity]

You need a qualified CO expert to look at the furnace. Does the new boiler and water heater vent into the same pipe?

You may have a new atmospheric boiler that has a draft hood. You could have such a high draft in the flue pipe which is creating a curtain/eddy effect which is making the boiler spill into the room. Your old boiler had a barometric damper with no draft hood. This made the boiler vent happily up the flue pipe. The fix to your issue would have a qualified CO/Combustion technician get rid of the draft hood and install a barometric damper with a spill switch to the new boiler and water heater.

I would also invest in a low level CO monitor. I would turn your appliances off until then.

[Mark325i]

Thanks for the reply. There is not separate hot water heater -- it is an indirect one running off another zone. The boiler, a Burnham ES2, is atmospheric and is connected to the existing, relined chimney. The flue damper is motorized. Since I have left the door to the utility area open I have had a zero reading on my new CO detector and zero from the fire department's more sophisticated one.

You need a qualified CO expert to look at the furnace. Does the new boiler and water heater vent into the same pipe?

You may have a new atmospheric boiler that has a draft hood. You could have such a high draft in the flue pipe which is creating a curtain/eddy effect which is making the boiler spill into the room. Your old boiler had a barometric damper with no draft hood. This made the boiler vent happily up the flue pipe. The fix to your issue would have a qualified CO/Combustion technician get rid of the draft hood and install a barometric damper with a spill switch to the new boiler and water heater.

I would also invest in a low level CO monitor. I would turn your appliances off until then.

[kdean1]

Th potential for trouble still exists if something as simple as closing a door gives rise to generating carbon monoxide.
DO NOT TAKE YOUR SAFETY FOR GRANTED.
You need to have your system inspected by someone trained in combustion analysis to provide a permanent solution.

[pwilliams]

This is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise, commentary, or ask questions of the OP here.

You can find the rules for posting and qualifications here.

Further infractions may result in loss of posting privileges.

[mechanical'al]

another thing is a co detector relies on humidity to carry the co to the detector!!!!

[beenthere]

pwilliams, this is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise, commentary or ask questions of the OP here.

You can find the rules for posting and qualifications here.

Your post has been deleted.
Further infractions may result in loss of posting privileges.

[pwilliams]

This is the Ask Our Pro's forum, and only Pro members that have been vetted by the AOPC may post advise, commentary, or ask questions of the OP here.

You can find the rules for posting and qualifications here.

Further infractions may result in loss of posting privileges.