Flame blowin' in the wind...

testeng · 10-21-2007, 05:52 PM

I have a Goodman GMP100-3 that has developed a problem since the inducer motor was replaced. The flame sensor is located at the burner that is furthest away from the igniter. When the gas is ignited, the flame in that furthest burner acts as if someone is blowing on it. The flame comes and goes and because the flame sensor is insufficiently heated, the gas shuts off. The furnace control waits briefly and ignites the gas again. After about 2 or 3 of these cycles, the flame stays on sufficiently long in the last burner to keep the sensor happy and the furnace continues to run. Has anyone ever seen this phenomenon before and perhaps can explain what is deficient in the system? Thanks.

Craig

testeng · 10-27-2007, 10:41 AM

Geeez guys. Did I stump the panel? If you guys can't figure this one out, what hope have I got if I call in a pro?

Craig

HvacWiz · 10-27-2007, 04:58 PM

Take burners out and clean them with wire brush, also make sure your gas presure is correct coming from the outlet side of gas vave. 3.5 inches of W.C. for natural gas 11.5 for propane

#CARRIERMAN · 10-27-2007, 08:12 PM

Hi testeng

Hvacwiz is correct with his diagnosis. If you still have the same problem after you clean the burners. You will need to pull and clean orfices as well. There are a small species of spiders that like to make their nest inside the orfices. Just remove them and use compressed air to clean. The reason for the blowing noise is change in either air velocity through burner or gas velocity in the orfice. I think you will be fine with Hvacwiz's response.

Good luck
Rusty

testeng · 10-28-2007, 04:11 PM

Thanks for the advice guys. Others I have talked to agree with your assessment. The furnace worked fine prior to replacement of a noisy inducer motor. The repairman was called out again and claimed that there was a piece of gasket material blocking the air flow. It seemed fine until he left and then reverted back to the same problem. I have been thinking that he put in the wrong inducer motor, but on the other hand, with all of the jarring of the system, particles may have dislodged and are now blocking orifices. If I decide to clean the system, I will definitely call in a pro because it looks to be a real bear to get the burners out. They are integrated into a chassis that holds the gas piping, so the chassis, gas piping to and through the valve, as well as the valve need to be removed. The furnace is 12 years old so an alternative is to just replace it. It is on the 2nd floor of all places and is quite noisy. Can anyone recommend a super quiet brand?