American Standard Freedom 78 Furnace - red/yellow flame blowback
I have an American Standard Freedom 78 furnace. When I turn on the furnace it starts fine with the blue flames injecting into the box. However, after a couple of minutes, there's 'blowback' (flames not fully going in, but backing up like a fireball) where the flames turn red/white/yellow. I know this is happening because I removed the service panel to inspect. Do you know what the problem is? Is this a serviceable issue or would I need to get a new furnace?
Probably going to need a new furnace. The heat exchanger may be plugged with rust/soot/carbon (next to impossible and impossible to clean properly on some units and extremely expensive to try) and may also be cracked. Air pressure from the fan goes thru the crack and pressurizes the heat exchanger and gives you that blowback/rollout which is EXTREMELY DANGEROUS AND WILL PRODUCE CARBON MONOXIDE. Need to get it checked by an experienced tech ASAP.
"Cut it twice and it is still too short".
The Following User Says Thank You to yuri For This Useful Post:
I also showed a video of the furnace to a heater service guy and he basically concluded the same. Thanks again and for the warning. BTW, I do not run the heater and the gas shut-off is on the off position.