Coleman DGAA056BDTA

[RonPeter]

I had this furnace installed 3 years ago and it has constantly given me problems, it will give the 3 flash's code, the company I bought it from has replaced the pressure switch 4-5 times and replaced the booster motor once, it will run for maybe 1 month or a little longer then stop working again after replacing the pressure switch. Now it is off warranty and is acting up again. I've had a tech out from a different company and we have checked to make sure the air pipe is clear and the pressure switch is definitely opening and closing, we even switched back to a manual thermostat from the programmable one I had to see if that was the problem. Yesterday it ran all day normally cycling off and on but with the LED light still flashing 3 times and today it isn't running at all. Could it be an intermittent problem with the control board? I did read where you said the contacts in the pressure switch may corrode but this fast seems a little crazy to me LOL. Any ideas? Thank you for your time and I think I included all the info I have.

[Robert]

The 3 flashes can be caused by:

Combustion Air Pipe damaged, loose ,leaking or blocked.
Booster Motor or Wheel dirty or faulty.
Pressure Switch bad.
Tubes to pressure switch kinked, clogged or loose.
No 24vac to one of the pressure switch wires (24vac from wire to ground).
Intermittent loss of the 24vac to wire on pressure switch.
Faulty control board.

I offer a $20 fee for troubleshooting in one on one email to go through the steps of testing. That may or may not uncover something that has been overlooked.


Thanks,
Robert