Small cracked heat exchanger really an immediate do-or-die-NOW problem?

[AC Power]

I wrestle trying to get my mind around the claimed dangers of a heat exchanger with a small crack in it. I know salesman LOVE it, as it is very convincing to homeowners, and since personal safety is implied, it's pretty much a "signed deal" for a new furnace. I believe I have so much evidence that small leaks of CO in your exchanger is no need to panic, rather, recognize that a new furnace is an eventuality. Of course, CO detectors are a must within the house, of which we have three (3).

 

[ShaunCorbs]

I’m guessing your system is warm air ?

 

[AC Power]

Yes, heating. Originally it was purely a fan forced natural gas furnace, atmospheric venting (same as the water heater, no draft motor), but I added central AC about 10yrs ago, so it also has an A-coil.

 

[king of pipes]

There no second chance with CO it will either make you and your loved ones feel ill or kill you is it worth the risk .

 

[ShaunCorbs]

It’s a no from me as with any crack doesn’t take much for it to split further

 

[AC Power]

There no second chance with CO it will either make you and your loved ones feel ill or kill you is it worth the risk .

True, there is no second chance. However, not one (of 3) of my CO detectors are triggering, that is, always showing 0% ppm of CO.

Additionally, think of this: How can I possibly turn three (3) burners on my natural gas range top appliance and the three CO detectors maintain a 0% ppm? Remember, of course, that this is an open flame, burning blue steady flame (as it should). The exhaust fan above the range is not near sufficient (by way of CFM) to exhaust adequately. Yet, CO detectors are fine! How then, could a small crack in a heat exchanger produce toxic levels to a fatal level? It makes no sense.

Too, with adequate oxygen intake from outside, one (1) oxygen molecule will bond with the CO particles, forming CO2, a non-toxic noxious gas. It makes us sleepy and tired, but its generally deemed as fatal. After all, that's the principle of parking garages with direct fire MUA and exhaust fans. The two (2) units must be interlocked so as to provide sufficient replacement of the air. CO levels won't build too high with the proper introduction of outside air.

Notwithstanding the initial heating of the heat exchanger (prior to fan start), there is higher air pressure outside the exchanger when the fan starts. When the fan starts, the positive static pressure outside exchanger prevents combustion gases from migrating into the supply air.

A lot of evidence, a small crack is nothing to worry about. Doesn't mean you ignore it...but, you need not panic. Get your funds together, arrange a suitable time with the installer, then change it.

 

[AC Power]

It’s a no from me as with any crack doesn’t take much for it to split further

I agree a split can grow, yes. But read my comment to "king of pipes". I don't feel a person needs to panic or freak out. Stay calm, don't panic, a small crack likely will take years to form into anything to worry about.

BTW - Upon installation of my a-frame evaporator coil, I observed the exchanger with mirrors and a inspection camera. There were no visible cracks. If you can't see a crack, then it's most definitely not worth worrying about anyways. Read above.

 

[king of pipes]

I wouldn't rely on co detectors 100% they are a aid but being battery powered ? They can and do fail , if your warm air unit is serviced by a fully trained engineer and found to be faulty then I wouldn't use it, but the choice is yours I cannot add anything further .

 

[hometech]

There no second chance with CO it will either make you and your loved ones feel ill or kill you is it worth the risk .

Indeed.It killed 0.0000000811% of the population in 2020 which means you twice as likely to win the lottery (1:45,057,474) than die of carbon monoxide poisoning.

 

[Chuck]

Indeed.It killed 0.0000000811% of the population in 2020 which means you twice as likely to win the lottery (1:45,057,474) than die of carbon monoxide poisoning.

Nope. There were 60 deaths from accidental CO poisoning in 2020 in England and Wales, which is 1000 times your figure. The 2013 figures, which I happen to have to hand, were 40 deaths, 200 people hospitalised and 4000 people needed to attend A&E for treatment.

Edit: Here's a reference supporting my figures:

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/260211/Carbon_Monoxide_Letter_2013_FinalforPub.pdf

 

[AC Power]

Nope. There were 60 deaths from accidental CO poisoning in 2020 in England and Wales, which is 1000 times your figure. The 2013 figures, which I happen to have to hand, were 40 deaths, 200 people hospitalised and 4000 people needed to attend A&E for treatment.

Edit: Here's a reference supporting my figures:

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/260211/Carbon_Monoxide_Letter_2013_FinalforPub.pdf

It does not surprise me there are many deaths from CO. I am curious to know where these deaths originated though. Vehicles left running in garages is a big problem (-suicides) as the fumes can migrate into the house, and the byproducts of gasoline is far more fatal than that of CO, while vehicle exhaust does contain CO. Natural gas is fairly clean burning, that's why they are permitted on forklifts in warehouses here in Canada...provided the building is not sealed up tight and there is no fresh air intake.

Good point though Chuck.

 

[ShaunCorbs]

Thread closed respect your pros advice