Coleman 92% efficient gas furnace less than 2 years old Model# G2FD046S17G. Will only blow cold air. The lower half of the furnace contains an access panel with a round plastic window, through the window there is a red-light that flashes 3 times and pauses for 2 seconds and flashes 3 times again (I assume this is some sort of troubleshooting light). Can anyone help me out as to what this may be? Thanks!

Look on the inside of the furnace blower door for a description of the flash codes for your furnace. They should be listed there with the wiring diagram. BTW the model you listed is for the A coil in the unit not the furnace model number itself. See for yourself click the link below.

http://www.colemanac.com/PDFFiles/03...001-B-1004.pdf

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Originally Posted by hvac1000

Look on the inside of the furnace blower door for a description of the flash codes for your furnace. They should be listed there with the wiring diagram. BTW the model you listed is for the A coil in the unit not the furnace model number itself. See for yourself click the link below.

http://www.colemanac.com/PDFFiles/03...001-B-1004.pdf

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Thanks for the fast reply! The error code appears to indicate that "the pressure switch is stuck open".

OK, I got it working now. Not sure how, didn't really do anything other than open up the access panels to figure out the LED code. It may just be temporary, but it is blowing hot air at the moment and the LED indicates normal operation. Thank you greatly for your help!

The issue has returned. Which is what I was afraid of. I found a manual of my furnace and located the pressure switch. It has two hoses coming out of it, one down into the Motor Inducer assembly that connects to the exhaust and the other goes up into cover-gas control. The pressure switch is the one labeled 10 in figure 1. I popped of a small yellow cap at the bottom of the vent tube as it goes into the motor inducer and some water came out, I am not sure this is normal or not but obviously water condenses in the exhaust. Any help would be greatly appreciated.

http://www.luxaire.com/PDFFiles/035-...001-D-0207.pdf

You said your furnace was a Coleman? What gives? Did the brand change? York,LUX,Coleman are from the same camp but I thought we were working on a Coleman?

See if any water is in the presssure switch. Blow into the little hoses to be sure they are clear with no water or debris. Shake the pressure swith out to be sure of no water and try the system. If still a no go then jump the pressure switch out of the circuit for test purposes only and try the system. Report back.

It is a Coleman, at least it is labeled as such. When I googled for the manual using the model number that is what came up. It appears to be the same furnace as everything is located where it says it is. I will go try your suggestions and report back. Thanks again for the prompt reply!

I disconnected the hoses from the cover gas control, I then proceeded to blow in this and their appeared to be no obstruction and I could hear the switch clicking. I then disconnected the hose from the motor inducer and sucked on this to verify the vacuum was working in both directions, there was no obstruction in this hose either and the switch appeared to be clicking as it should. I reconnected everything and fired the furnace back up and it still did not want to work.

Next I removed the switch to inspect it and disconnected all the wires leading to it, there is not much to look at as the switch does not appear to be made to be taken apart. In a last ditch effort I blew on the hose leading into the inducer motor, which is the direction the air should be flowing, and I sucked on the hose coming from the gas cover (not sure if that was a good idea or not, but I'm still here ;) ) I re-attached the switch and attached the hoses and wires back up to it and fired the furnace up. And Voilà it worked, I do not believe there was any obstruction and am not sure if the steps I took actually fixed the problem or if it just decided to start working again. I will monitor it and see if it stays running. If it stops working again I will use the same steps that appeared to be successful and will go from there. Thanks for your help hvac1000!

Glad you got it going and have some heat.

Mine was flashing the same code and I got a repairman to come out because it wouldn't light and when it did light the air coming out the vents wasn't very hot.
He thought it was possibly a bad pressure switch but he found 2 spiders on the back side of the orifice. I don't know if it was related or not but after he left yesterday mouning we were using our electric fireplace until bed time and when the furnace tried to kick on it coaded that the pressure failed to close.
I turned the thermostat down so the pre ignite motor would stop running and then kicked the thermostat back up and it ran fine all night. 2 year old Red T by Colman.

I have a Colemand furnace Model: DGAT075BDF which quit blowing warm air and the fan just kept running. It had the code of 4 flashes which is limit switch open. I got technician out to look at and it was the aux switch which has a manual reset. The problem is that this furnace had a kit 37323712001 installed with it which has this aux switch mounted on the side of blower compartment with a tiny wire. It could not be remounted, so it is just taped in place. Whenever the tape dries out, it falls, touches metal and blows a fuse. The tech does not know how to mount it securely and I am tired of changing fuses plus am adraid to trust it for overnight in the winter. Please let me know how I can mount it securely.

The installer was not very good. That yellow cap you removed should have had a hose attached to it. That hose should have gone to a trap. That trap then drains to an approved lection. http://blog.theaircoguy.com/

Sounds like you have a lazy tech. Tell him he needs to remove the blower from the furnace to properly attach that limit switch. These switches are there for safety reasons and if your tech is not attaching them safely then how safe will this furnace run. Don't go cheap when it comes to you and/your family's safety. Please...