Heat Issue

[Dtaylor]

Our last trip out our heat failed to work. The fan would come on but it sounds like the gas is not igniting. The fan runs for a period and shuts off. I pulled the access panel and I can see a light flashing on the top of the unit.

The issue is not gas flow prior to the heat unit as I lite the stove and let it burn for some time to be sure along with running the frige on gas.

Any ideas on what the problem might be and how to fix?

[Dtaylor]

Old-Biscuit wrote:
Atwood Furnace Error Codes

Fault LED Indication

Internal Circuit Board fault Steady on, no flashing

Limit switch/Airflow problems 1 flash with 3-second pause

Flame Sense fault 2 flashes with 3-second pause

Ignition Lockout Fault 3 flashes with 3-second pause


What error code do you have?

I will have to check again this weekend but I think it is a series of 3 flashes.

Where is the best place to order a Dino board from??

[Old-Biscuit]

Atwood Furnace Error Codes

Fault LED Indication

Internal Circuit Board fault Steady on, no flashing

Limit switch/Airflow problems 1 flash with 3-second pause

Flame Sense fault 2 flashes with 3-second pause

Ignition Lockout Fault 3 flashes with 3-second pause


What error code do you have?

[rav]

I had the same problem last fall- cleaned all the connections and it's been working fine every since. great advice above

[wa8yxm]

I will bet the light is flashing in groups of 3 blinks.

On this ignore the first line (1) we know the T-stat is working.. But with the second line, start reading...

I am told I missed one possible issue, Bad connections (12 volt supply) can mimic bad battery/low voltage.

When the T-Stat calls for heat the control board starts the blower (1)
The blower blows closing the sail switch (2)
The control board then opens the gas valve (3) and begins sparking (4.1)
Gas Flows (5) And ignitets (4.2)
The flame heats the flame sensor (5)
The flame sensor sends .480 volts to the control board (6)
which then detects the .480 and continues operation (*)
When the T-stat says "Enough already" (RV is now warm)
The control board shuts off the gas flow (*)
and then turns off the blower after a cool down (*)

*: At nearly every step the control board is involved. IF IT IS BAD, things will not work.. I recommend replacement boards from Dinosaur boards.. When Mine went out the Dino board was less than half the price and when opened the box the quality of construction and workmanship, and then design was very clear to my trained eyes.

1: No 12 volt to furnace, blower motor shot
2: Low 12 volt, air ducts clogged, blower "obstructed" bad sail switch
3: Bad solenoid, Clogged Gas Jet
4: .1: Bad ignition circuit (high voltage) on control board. .2: Points too wide (Very common it seems)
5: These do not often fail but they can
5: Bad connection, NOTE:
5 and * Bad wire.

* applies to all steps by the way So does bad wire/connection.

[Dog_Trainer]

I had a similar problem with mine and it turned out to be the igniter had somehow moved and it was no longer getting the spark. I reset it and it has fired up every time since.

[RoyB]

Locate the sail switch and try some WD40 onit. Make sure it moves freely. Its purpose is to shut down your heater in case of blower failure. Lint and debris gets into the sail switch operation preventing it to work - very common problem...

Another possible failure point if you have propane making it to the heater would be the heater control board which runs off of 12VDC. This could be just the 12VDC has been shut diwn or drained batteries etc... Perhaps your battery disconnect switch has been engaged...

Roy Ken

[TucsonJim]

Dtaylor wrote:
Our last trip out our heat failed to work. The fan would come on but it sounds like the gas is not igniting. The fan runs for a period and shuts off. I pulled the access panel and I can see a light flashing on the top of the unit.

The issue is not gas flow prior to the heat unit as I lite the stove and let it burn for some time to be sure along with running the frige on gas.

Any ideas on what the problem might be and how to fix?

It sounds to me like a defective sail switch. Check out this site and it will give you some troubleshooting techniques. I'd start with the sail switch:

RV furnace troubleshooting