Coleman DGAA077BDTA green light flashes 3 times

[otis]

I live in Oklahoma in a single wide mobile home.

I have a Coleman gas furnace model:DGGAA077BDTA

Green light blinks three times.

Called first service tech three weeks ago.

He came and took a tube off the pressure switch blew and sucked on a tube put it back together. I asked him what can be done to fix this problem. He said turn the furnace off at the thermostat and then take the hose loose from the pressure switch and gently blow and suck. Turn furnace back on. Charged me $130 and left. It worked until about 4 am.

Called a different service tech out on Dec 5

1. He cleaned the burned assembly.
2. inspected the heat exchange
3. replaced the assembly booster with motor
4. climbed on top of roof and inspected the flue
5. checked the pressure switch
put everything back together and the green light still blinked three times.

He was inspecting the main board and found a few of the wires loose. Pushed those back into there little holding clip. Turned the heater back on and no flashing green light.

Got up around 8am and flashing green light 3 times again. I turned the heater off gave it a couple of minutes and turned it back on. It just finished a cycle still has solid green light.

The main time I get the error code is when the heater comes on a lot (early in the morning 3 am to 6 am).

So the service tech can’t figure out what is wrong with the furnace.

Any advice would be greatly appreciated.

[DaleM]

Didn't any of those guys replace the pressure switch??

[otis]

Thanks DaleM

Pressure switch was replaced.

Had the circuit board replaced today. Heater worked for about 4 cycles then back to the 3 flashing lights.

After the Heat guy replace the board, he said "you might want to get your A coil cleaned" ($300 from him). So I cleaned my coil after the green light started flashing that was around 4 pm.
It is 10 pm now and so far so good.

[otis]

Stopped working again around 5 am.
Husband was up and tried everything to get it going again.
The only thing that works now to turn off the heater at the thermostat and wait 5 to 10 minutes then turn heater back on and it will fire up and run about 3 to 4 cycle before quitting again.

I replaced this system back in 2005 and am really thinking about replacing it again. Looks like Coleman's are only good for 7 to 8 years. What ever happened to Quality?

[upstateny]

I have a similar unit DGAH077BBSB installed in 2007.
Get a "User's Information, maintenance and Service Manual" may be able to get one from Distributor: Stylecrest / 801 W.37th St. Bldg. #7 Wichita KS 67219; or from the manufacturer: York International - Consumer Relations 5005 York Dr. Norman OK 73069. Also note ww.source1parts.com
All the trouble codes are in the manual.

My manual states the three flashes: = "Combustion air pressure switch failed to close, this indicates the normally open pressure switch contact did not close at the beginning of the heat cycle. This could be caused by: faulty inducer / blocked vent pipe / broken pressure switch / faulty pressure switch".
Once I had a similar problem, and found a mice nest blocking the vent pipe. With my new furnace, I had four flashes and found the old original floor vents to be inadequate. They were abandoned for new 6" insulated vent tubing and a new plenum box in the floor. My trailer is circa 1955. Hope this helps. [email protected]

[DaleM]

Try this, turn the furnace OFF at the rocker switch in the furnace, take the red and white thermostat wires off at the furnace, twist them together, turn the switch back on. Furnace should fire up. After about 5 minutes of run time untwist the wires. Furnace should cycle down, comb. motor off, burner off, then fan off. Do that several times over an hour or so and see if the furnace ever fails to come on. If so replace the tstat. Only ran into to it once but it can happen.

You could also check to see what "size" pressure switch was put in. There are ratings on them, .30, .20, .18, etc. Using a "lighter" switch will help as the furnace ages and things don't work as "perfectly" as they did when new. A .18 would be best in there.