diagnostic light 3 flashes

[Tcollin]

coleman dgaa056

Went to turn the heat on last saturday and it would not kick on. I checked the diagnostic and saw 3 flashes ( pressure swith failed to open). I order the part from you Sunday part#024-27666-000. I received it yesterday. I went and installed it this morning and still nothing is working. I still have the same fault code. Any ideas?

[Mark]

Basically something is probably triggering your pressure switch (the whole purpose of that part).

When you first start your furnace, does your booster motor start? It needs to start to build pressure to trigger your pressure switch.

If your heat exchanger is severely cracked, air pressure may not be able to build enough to trip the pressure switch.

Could also be something blocking the tubes to the pressure switch?

Also, post the whole model number of your furnace to be of further help. Your missing the last few letters.

Mark

[Tcollin]

coleman dgaa056bdta

The only thing I here is the relays click than the blower motor kicks on.

[Mark]

When your furnace first calls for heat, the booster motor should first come on. That's the small motor located at the side of the furnace (the tubes from the pressure switch lead to it). If it's not running, then there's an issue with it.

Part number for the booster assembly for your furnace is 373-19801-820 and can be seen and ordered from this page: http://www.mobilehomerepair.com/ColemanGas.html

Of course you'll want to be sure that the booster assembly is receiving power and it not running isn't caused by something like that.

Mark

[Tcollin]

I will check on that and see that there is power, if I do have to buy the booster, can I send the previous part I bought from you back for a refund since I dont need it?

[Robert]

Hi,

You can return it if it has not been installed and used yet. The Pressure Switch is a common problem and eventually they will fail.

May want to keep as a backup for an emergency in future, but that's up to you.



Thanks,
Robert

[Tcollin]

When checking to see if power is going to the motor, which wire is the hot and ground?? What type of voltage shout I be getting? also when testing should the furness be in the running position?

[Robert]

Set t-stat to call for Heat. Wait 3 seconds after call, then test across W and C at control board. IF 24-28vac is present, test across pins 4 and 6 (2 black wires) at the 6 pin connector at control board for 120vac.


IF you read 0vac at 4 and 6 with 24-28vac at W and C, replace the board.


IF you have 24-28vac at W and C AND 120vac at 4 and 6, replace the booster assembly.

Make sure you have 18 gauge t-stat wire with no pinched or damaged wire going from t-stat to the control board.



Take care and best wishes,
Robert

[Tcollin]

I just received my booster assembly and want to know if there was a way to tell which of the 2 wires go where. I marked one of the wires but the tape fell off. I just want to make sure I hook everything back up right. Thanks again!

[Tcollin]

can some one get to my question?? I need to get it back together it is supposed to get cold the next few nights.. Thanks

[Robert]

One wire to pin #6 and the other wire to pin #4 on the 6 pin connector on the control board.


Thanks,
Robert