Goodman Furnace Mod # GMPN100-4

big waynester

It will run for about 5 min, then shut off, I get 3 blinks on the status light. I have no book with this unit, so I don't know what this means, but it was installed in late 1999. Is there any thing I can do? I hate to call the guy that installed this.

Unregistered

You should be able to find a diagnostig cade inside the unit or on the control module itself. If I was to take a guess i would say the unit is over heating and tripping your limit switch. Make sure the filters and coil are clean that switch will open in the low to mid 200's.

Bjd

Most flash codes are also labled on the inside cover of the unit, locate the flash codes and get back to us.

bjd

big waynester

Doh! I was looking on the inside of the furnace for the codes, they were on the cover. The error is "Pressure Switch Failure to close" is says to check, Ventor, Pressure switch, and Vent blockage.

While the furnace was running, since it is cold, I can see it is venting.
Can someone tell me how to check the other things?

Another thing this is a down flow furnace, it is in the mezzanine in my barn, I don't have the furnace on all the time, the condensation line runs along the ceiling of my barn to the other side where the drain is. If water froze up in the line, would it cause this error?

big waynester

the pressure switch had water in it.Is this normal? I tested the pressure switch by blowing air into it and ataching a meter, the switch seems OK

big waynester

I think I kind of have it fixed, to much condensation in the vent blower, backed up to the pressure switch hose and got into switch, now I got to figure why this happened

Allen

Check to make sure that the vent for the exhaust is at a downflow angle toward the furnace.if it's sagging water will build up

Bjd

You bet your a$$ that would cause that type of failure, water in the switch line frozen will not allow the switch to operate. I work on a bunch of these units that are in a skate rink, its very common for this to happen to them.

BJD