Another Goodman....

Ok - I have another Goodman (GMPN100-4 Rev A) that I am working on that I have some questions about.

I have come across a few condensing Goodman's this season that have what I see as significant flame rollout during start, but do not trip the rollout switch.

Question is, if it doesn't trip the switch, is it really considered rollout? Almost all other furnaces that I have worked on do not do this except Goodman.

A couple of readings - 7.2"IWG gas in - 3.6"IWC out
Exhaust vent is short and completely open.

Didn't have the combustion analyzer with me (shame on me) going back today to do a combustion check. Does anyone know the proper CO for this furnace? I can't seem to find it on any of the data.

After tearing it apart found inducer motor outlet and collector box showing signs of serious overheating - never seen that before (pictures attached)

thoughts?Attachment 359041Attachment 359051

Correct orifices installed? What was your temp rise?

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Originally Posted by ParamountAir

Ok - I have another Goodman (GMPN100-4 Rev A) that I am working on that I have some questions about.

I have come across a few condensing Goodman's this season that have what I see as significant flame rollout during start, but do not trip the rollout switch.

Question is, if it doesn't trip the switch, is it really considered rollout? Almost all other furnaces that I have worked on do not do this except Goodman.

A couple of readings - 7.2"IWG gas in - 3.6"IWC out
Exhaust vent is short and completely open.

Didn't have the combustion analyzer with me (shame on me) going back today to do a combustion check. Does anyone know the proper CO for this furnace? I can't seem to find it on any of the data.

After tearing it apart found inducer motor outlet and collector box showing signs of serious overheating - never seen that before (pictures attached)

thoughts?Attachment 359041Attachment 359051

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Run across this same issue with a goodman this season. Unit was way oversized for the home and the temp rise was off the charts coupled with weak inducer motor and when i looked into the heat exchanger there was some nice 4" cracks along the back side going up on all burner chambers. There was also alot of corrosion from the flame rollout around the burners.

Venting correct?
Not too short, there are minimum lengths.

See that a lot where the gasket dividing the secondary had failed but always figured the gasket was the cause of the overheating, it let's the exhaust bypass the secondary and ruins the orifice. Then it snowballs from there.

Inducer obviously not doing its job one way or the other, whether weak/bad inducer motor or something keeping it from drawing the flame through heat exchanger and out the flue (cracked exchanger or clogged flue). Basically I agree with the "barrettservices"