Heat N Glo Northstar producing Carbon Monoxide

Bcurley

Member
Nov 11, 2014
27
Long Island, NY
Hi all, I need some brainstorming on this one...

I am on my 5th season of burning the Northstar with no issues until now. This past Friday (11/8) was my first burn of the season. I burned 2 loads and went to bed. The fire was about half way through its burn when I went to sleep. About 4:30am my family was woken up by the carbon monoxide detectors going off. I immediately evacuated and called the fire dept. They came in and confirmed the CO in the house. Before evacuating the house I distinctly remember turning off the fan to the fireplace. The fire dept went throughout the house and the highest levels were coming from upstairs. We all assumed it was the gas furnace in the attic. I had an HVAC guy at my house to check everything out and all looked good. I wasn't using my furnaces during the day as we thought that was the issue and I continued to use the fireplace. Later in the day I was able to get a handheld carbon monoxide detector and went throughout the house with it and all levels were zero. We made sure to turn on the heat to the house and tested all equipment and everything came up negative.

Saturday night we all went to bed and I kept all furnaces off and had the fire going. Again at 5:30am this morning the carbon monoxide detectors went off. I evacuate again and grab the handheld and start to chase the highest levels. First went to the attic and the levels dropped. Next went downstairs and levels started to climb. Went into the room where the fireplace is and the the levels spiked to 250ppm. I immediately shut the fan to the fireplace off and the levels started to drop right away. I am trained on how to use these meters as I am a hazmat technician in my law enforcement job. I vent the house out and 20 minutes later all is good. The fireplace is 100% the culprit of the carbon monoxide. It is only happening when it gets to the smoldering stage of the fire as both nights were after about 12 hours from last start of the fire.

I checked the chimney this past spring and it was clean as I burned well seasoned wood mixed with envi blocks all season. I plan on sweeping the chimney regardless of how it looks and replacing the baffle board and ceramic blanket. Besides cleaning the inside of the box last week and replacing the ACC timer I haven't done anything else to the fireplace.

Does anyone have any thoughts as to what may be causing this and how to prevent it? This is a life threatening problem and needs to be remedied!! I plan on calling HHT on Monday as well. Thanks for any input.
 

begreen

Mooderator
Staff member
Nov 18, 2005
79,090
South Puget Sound, WA
Sounds like draft is insufficient and possibly reversing. The easiest first place to check is the chimney, especially the chimney cap screen if there is one.

Where is the fireplace located, main floor or basement? Does the fireplace have an outside air supply? If so, check that the intake screen is clear.
 

Bcurley

Member
Nov 11, 2014
27
Long Island, NY
Sounds like draft is insufficient and possibly reversing. The easiest first place to check is the chimney, especially the chimney cap screen if there is one.

Where is the fireplace located, main floor or basement? Does the fireplace have an outside air supply? If so, check that the intake screen is clear.
‘The fireplace is located on the main floor and it does have an outside air supply. I will be checking the chimney tomorrow. The cap on the chimney is intact, so I doubt ther was anything in there. I was thinking same about insufficient draft, but the fire was working well all day and this was only happening at the smoldering stage.
 

tommyH

New Member
Nov 10, 2019
4
Alabama
I have nothing to suggest for you except maybe the gasket(s) need changing. But....Thank goodness we have CO detectors.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
19,050
central pa
‘The fireplace is located on the main floor and it does have an outside air supply. I will be checking the chimney tomorrow. The cap on the chimney is intact, so I doubt ther was anything in there. I was thinking same about insufficient draft, but the fire was working well all day and this was only happening at the smoldering stage.
That is when draft is the weakest. And when high concentrations of Co are produced
 

moresnow

Minister of Fire
Jan 13, 2015
942
Iowa

moresnow

Minister of Fire
Jan 13, 2015
942
Iowa
This is the cap I have. It is free of any creosote on it.
If its truly clean your good to go. That cap looks very susceptible to buildup on the inside. My opinion only. Not saying its dirty inside but have you popped it off for a visual since these troubles started? Possibly worth a peek. Good luck.