Goodman GKS9 1155DX Problem

[Luke72085]

Hello folks!

I recently had a new furnace installed and it has not worked right ever since. The technician that installed it says it is working as it should but I know it is not.

The furnace I have is a Goodman GKS9 1155DX.

Currently the light on the front of the furnace is blinking 3 times on and off. After a bit of research I found that this is likely a pressure switch problem. If I take the bottom panel off of the furnace (the one that houses the main blower motor) and put it back on - the problem resolves itself for about 30 to 40 minutes. The red light remains constant - indicating proper operation. After a running for a while it starts to screw up.

Here's what starts to - The blower will run nearly constantly. The heating element will turn on and off periodically. As you may have guessed, since the blower is running constantly - it blows cold air into the house in the time that the heating element is off. Eventually the blower will turn off. The heating element turns on, heats the coils for about 15 seconds and as soon as the blower turns on, the heating element turns off. After a couple of minutes of this cycle - the furnace will stop working entirely and the little red light starts to blink 3 times.

I have tried taking off the rubber tubing that connects the vent blower to the pressure switch to make sure that it is not clogged. After inspecting it, I replaced it. The problem persists.
I have tried turning the power off to the furnace for about 1 minute - then back on to no avail.

I would really appreciate any input - I am tired of running space heaters to keep the place warm.

Thanks!

Luke

[Freon]

I would TEMPORARILY jumper the vent motor pressure sensor and see if the problem persists. That will eliminate one possibility.

The main burner cycling could be due to the vent motor pressure or it could be due to the high limit sensor or even the roll-out sensor. If you can, observe the flame so you can see as the furnace burner stars and stops that the flame stays in the combustion chamber.

I would also check how the furnace is vented to make sure it's done to the manufacturer's specs. The main blower motor behavior could suggest a flaky control board. Try setting the FAN to ON (from AUTO) at the thermostat and see if the behavior changes.

Your furnace is like a black box... we need to shake it around to find out what's happening.