Will gas furnace emit carbon monoxide?

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Posted by: from Maple
1/28/2016 at 3:27:36 PM

Will a 10 year old gas furnace emit carbon monoxide?

Is it a waste of money to hire a HVAC contractor to inspect the gas furnace?

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John Carlo from Bossio Design in Thunder Bay
Date/Time1/28/2016 at 4:27:43 PM


Yes to your question. You may want to upgrade to a higher efficient furnace or if it not in your budget you can have a free instalation and rent like some people do with their hot water tanks.

Also it's the law in some regions to have a carbon dioxide detectors on every floor.

I hope the information I've given you was helpful.

Best regards,

Bossio Global

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Martin in Maple
Date/Time1/28/2016 at 4:31:21 PM

John Carlo from Bossio Global in Toronto,

Will a 10 year old gas furnace emit carbon monoxide? YES???????

Is it a waste of money to hire a HVAC contractor to inspect the gas furnace? YES??????

Please confirm that the YES applies to BOTH questions.


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Date/Time1/28/2016 at 5:54:38 PM

Yes to your question, carbon monoxide can and will as your furnace gets older and another factor is the quality of air supplied to your furnace. A number of factors come into place to make this happen. Furnace's now are by law high efficient and furnace company's have changed their furnaces to make them better and more efficient for the home owner.

Yes to your second question. If you are uneasy with how old your furnace is and want to make sure your furnace is still ok after all these years my personal suggestion is to hire a company to inspect your furnace to give you piece of mind.

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Date/Time1/29/2016 at 9:43:07 AM

Hi Martin,

Yes most definitely a 10 year old furnace can emit harmful levels of Carbon Monoxide. In fact any furnace can.

The biggest culprit is a cracked heat exchanger (manifold). While furnaces are well made and even the cheapest models are highly efficient, contributing factors like dirty filters, or oversized furnaces can have very serious adverse effects on the life of a furnace.

On your furnace there is usually a small window that you can peer into to see an LED fault code. The legend for the flashing lights is usually on the inside of the furnace panel.

If you are able to see the flame unit, either through the window, or from the main access panel, ensure that the flame is blue and not flickering yellow (an indication of possible CO release).

While I cannot recommend opening up and poking around in your furnace (as this can be more dangerous than the CO), if you have a reason to ask this question, it shows that you have some reason for concern. Carbon Monoxide is a very serious concern as it is completely odourless and invisible to the eye yet lethal to your homes occupants, it is definitely worth the investment to have a company check it out.

If they discover a cracked heat exchanger (for example), they are required to "tag" and "lockout" that furnace. This will mean you will be required (in this climate) to get a new one immediately so be ready.

If they do discover a crack, ask to see it. Unfortunately the possibility exists for a less scrupulous individual to make a false statement if it results in the purchase of a new furnace.

In the meantime, change the batteries, or purchase a few CO detectors and place them around your home (not within 5' of a combustible unit like fireplace, furnace, stove, etc.) If possible, and far preferred to battery operated units, have CO detectors hard wired into your electrical system on the same circuit as a main hallway light. That way they are always working and if the breaker trips, you will know right away when the light doesn't work.

I have attached a copy of a picture of a cracked heat exchanger for your reference.

Best of Luck and be safe.

Jason Irving

Cedarfalls Building Consultants Limited

Will gas furnace emit carbon monoxide?

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