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Luxaire GM9 furnace approximately 2yrs old. When call for heat is sent, the fan turns on and runs about 5 seconds then the LED goes from Green to Amber and the fan turns off. Something clicks and the LED goes back to Green, the fan starts and shuts off in 5 seconds / LED changes to Amber. Cycle will repeat endlessly. Any ideas?

Submitted: 35 days and 23 hours ago.

Category: HVAC

Value: $15

Status: CLOSED

Make : Luxaire
Model : GM9

Already Tried:
Working with a factory service tech, we tried 'jumping' the control board by removing all the wires on the furnace and putting a jumper between white and red. It worked a few days ago but it not now.

Posted by Kenton Guidry 35 days and 23 hours ago.

Info Request

Are you refering to the draft induced fan, or the indoor blower?

35 days and 23 hours ago.

Reply

Not sure if I know the difference but it seems to be the fan that pushes air through the ducts to cool / heat the house.

Posted by Kenton Guidry 35 days and 23 hours ago.

Info Request

Below is a picture of a draft inducer fan.

View Full Image

35 days and 23 hours ago.

Reply

Yes, that appears to be it. it starts, run a few seconds and stops. I hear clicking from the control board and the process repeats. Any ideas?

Posted by Kenton Guidry 35 days and 23 hours ago.

Answer

Check the rubber hose that connects the air pressure switch to the draft inducer fan for any cracks, or damage.

Then clean out the fittings that the hose attaches to.

Below is a picture of the pressure switch.

Turn the furnace off for one full minute to restart the system.

View Full Image

35 days and 22 hours ago.

Reply

I have the pressure switch out - is it normal for it to have water in it? Can I test run the furnace with the switch out / hoses disconnected to see if will keep running?

Posted by Kenton Guidry 35 days and 22 hours ago.

Answer

There should not be water in the pressure switch.

You can test the system by installing a jumper between the two wires you removed from the pressure switch.

35 days and 22 hours ago.

Reply

OK, I was looking the wrong thing - I was looking at some type of a filter that the condensation drains into before going into the floor drain. I checked the hose on the pressure sensor and they seem fine. I blew through both hoses and there didn't seem to be any restriction. I turned the power off at the load center for several minutes - same problem / no change. Any other ideas?

Posted by Kenton Guidry 35 days and 22 hours ago.

Info Request

Jump the air pressure switch. See if the furnace will start.

This can only be done for testing purposes.

35 days and 22 hours ago.

Reply

OK, this is probably a dumb question but I 'jumped' the pressure switch by putting a jumper wire between the two wires that connect to the pressure switch. When I tried to start the furnance, I got an error code indicating the pressure switch was stuck in the 'closed' position (2 red flashes) and the fan would not run at all. When I just left the wires disconnected from the pressure switch, the fan started and stayed running but I got a different error code - 3 red flashes, indicating the pressure switch didn't close after being induced. Did I 'jump' it correctly and does this help with the diagnosis?

Posted by Kenton Guidry 35 days and 22 hours ago.

Info Request

Wait for the fan to start when you jump the switch.

You are doing it right.

35 days and 22 hours ago.

Reply

OK, that worked. The fan started, I 'jumped' the pressure switch and the burner kicked in - I saw the flame. What does it mean? Bad pressure switch or something more expensive?

Accepted Answer

The pressure switch is faulty.

Accepts:
Expert:	Kenton Guidry
Pos. Feedback:	98.8 %
Answered:	10/18/2009

HVAC Technician

EPA issued refrigeration license, College certificate, and 7 years in field.

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Optional Information

Make : LuxaireModel : GM9 Already Tried: Working with a factory service tech, we tried 'jumping' the control board by removing all the wires on the furnace and putting a jumper between white and red. It worked a few days ago but it not now.

Info Request

Are you refering to the draft induced fan, or the indoor blower?

Reply

Not sure if I know the difference but it seems to be the fan that pushes air through the ducts to cool / heat the house.

Info Request

Below is a picture of a draft inducer fan. View Full Image

Reply

Yes, that appears to be it. it starts, run a few seconds and stops. I hear clicking from the control board and the process repeats. Any ideas?

Answer

Check the rubber hose that connects the air pressure switch to the draft inducer fan for any cracks, or damage. Then clean out the fittings that the hose attaches to. Below is a picture of the pressure switch. Turn the furnace off for one full minute to restart the system. View Full Image

Reply

I have the pressure switch out - is it normal for it to have water in it? Can I test run the furnace with the switch out / hoses disconnected to see if will keep running?

Answer

There should not be water in the pressure switch. You can test the system by installing a jumper between the two wires you removed from the pressure switch.

Reply

Info Request

Jump the air pressure switch. See if the furnace will start. This can only be done for testing purposes.

Reply

Info Request

Wait for the fan to start when you jump the switch. You are doing it right.

Reply

OK, that worked. The fan started, I 'jumped' the pressure switch and the burner kicked in - I saw the flame. What does it mean? Bad pressure switch or something more expensive?

Accepted Answer

The pressure switch is faulty.

Related HVAC Questions

Make : Luxaire
Model : GM9

Already Tried:
Working with a factory service tech, we tried 'jumping' the control board by removing all the wires on the furnace and putting a jumper between white and red. It worked a few days ago but it not now.

Below is a picture of a draft inducer fan.

View Full Image

Check the rubber hose that connects the air pressure switch to the draft inducer fan for any cracks, or damage.

Then clean out the fittings that the hose attaches to.

Below is a picture of the pressure switch.

Turn the furnace off for one full minute to restart the system.

View Full Image

There should not be water in the pressure switch.

You can test the system by installing a jumper between the two wires you removed from the pressure switch.

Jump the air pressure switch. See if the furnace will start.

This can only be done for testing purposes.

Wait for the fan to start when you jump the switch.

You are doing it right.