Damper failed - CO Alarms galore

Aberagejoemn

I'll try to keep this brief and to the point:
I have a one pipe steam system - Burnham Boiler is 2004.
Minnesota location.

In March of this year I had the damper on the boiler exhaust replaced as the original had failed and was stuck closed causing all the exhaust to build in the basement.

Fast forward to tonight - I get home and the carbon monoxide alarm was chirping in the boiler room, I killed power to the boiler right away (which was running). Then did all I could to vent the basement.

I checked the position of the damper and it appeared to be open when I killed the power to the boiler (which is odd).

I have since waited for the CO alarms to stop. I changed the manual toggle switch on the damper to be always open. I also took a pliers and manually opened the damper (so the damper stub out blade is vertical).

Anything else I can do/check before getting a pro in tomorrow?

Jamie Hall

Do your have any way to check the draught in the chimney? I don't suppose you smoke -- but any way of making a little light smoke to see if it gets sucked into the flue and up the chimney? I'm thinking of a potential flue blockage...

pedmec

Check to make sure your chimney is not obstructed. You could have animals nesting on top or dead ones falling to the bottom blocking the flue and restricting the flue gas from getting out. That's assuming that the CO alarm was triggered by spillage from your boiler and not another appliance.

Aberagejoemn

Thanks for both of the replies. The only other appliance venting through the chimney is the water heater which I'm relatively confident wasn't running at the time. I did have the chimney cap/screen replaced in 2011 - but worth looking to see if it fell off and something got in.

Assuming that it's not the flue - is it possible the boiler told the damper to close prematurely? The more I think about the old damper and now this one is that the boiler (which was still running) told the damper to close... anyway to check for that?

Alternatively, should I simply leave it locked open and move on with my life?

Thank you again for the help!

pedmec

I'm concerned that its not the boiler. Burnham independence steam boilers have rear draft hoods that should have a spill switch mounted on the back of the drafthood to shutdown the boiler in the event of a spillage. You should check that it hasn't been removed and bypassed. Not good. And they do work.

109A_5

Hello @Aberagejoemn,
Typically the thermostat commands the Damper to open. Once the Damper opens all the way the Damper's End Switch gives the Boiler the call for heat. Maybe yours is wired wrong.

tim smith

If vent damper was open my 1st guess without seeing it is blocked chimney. Other possibility is sooted up heat exchanger with gasses rolling out from fire box. With the damper open on boiler flue and boiler off, run a lit lighter around the edge of flue diverter and see if it pulls flame in towards the diverter, that was it will give you an idea if chimney is drawing.

109A_5

Hello @Aberagejoemn,
Thermostat, then Damper then Ignition.
Some wiring examples;

pedmec

The 2004 burnham independence would have the spill switch and rollout after the damper circuit. So the damper would be open with a failed spill switch or rollout switch. So for him to have an issue with the damper closed and get ignition is almost none existent. It’s almost impossible for the end to engage with the damper close. If for some reason you got ignition with damper closed you would trip the spill switch on the rear draft hood. If you got flame rollout the rollout switch would trip. This is provided theses safety’s have been compromised. You need to check the operation of the damper to see the position it is in when you get CO alarm. 

HVACNUT

Get the boiler and water heater checked by a qualified tech with a manometer and combustion analyzer. He or she will be able to check draft as well. 
What type of chimney?

The flue damper is for efficiency and doesn't need to close, but those burners aren't firing with the damper closed. Unless someone did some funky rewiring.