Goodman Nightmare

[Ted1]

Ok guys I a home remodeler/contractor so here included in this post I have sent the following letter to Goodman, any ideas would be greatly appreciated. Thanks! Goodman help as good as a rusted out muffler!

December 29, 2006


Attention: CEO & Technical Service Department
Goodman Manufacturing Co.
2550 North Loop West, Suite 400
Houston, TX. 77092


Dear Goodman CEO & Technical Service,

I would like to start of this letter by stating over the years I have purchased (3) complete Goodman gas furnace & AC units. Until my last purchase which occurred in December 2003 I have had little or no problems with your units.

I have a persistent problem with my present condensing gas furnace which has left both my qualified installer (blank) and me at a loss of cause.

The unit is Goodman model # GMNT 100-4.
The unit serial # is 0201633333.

In an attempt to remain brief I will try to explain my present situation below.

When using the furnace on demand for heat, the blower, heat and exhaust all work properly, no trouble codes on the circuit board flash. Shortly after the unit has gone through the shutdown cycle of 150 seconds the unit appears to have shutdown.

Several minutes later the blower motor and exhaust fan cycle on and off every 4-5 minutes. The unit then shuts down for several minutes then restarts the cycle over and over again with these cycles lasting as long as two to three hours before completely stopping. These cycles are not calling for heat during this time.

Here are the specifics completed in an attempt to repair the problem:

1. Upper limit switch replaced.
2. Circuit board replaced two times over two year period
3. All condensation hoses are open and clear.
4. All thermostatic wires replaced.
5. Thermostat taken from circuit furnace will continue to cycle.
6. Blower motor is powered by a dedicated 20 amp. circuit.
7. The unit has a ground through the external on/off mounted on unit.

Any ideas or has anyone encountered this problem before?

[t527ed]

on #5 how was t stat removed from circuit? what type of t stat?

[Senior Tech]

Unfortunately, due to site rules we as members can not discuss technical issues with the general public.

Thank you for your cooperation.