When I turn on the furnace, blower comes on for a few seconds, then the gas and ignitor - it ignites and burns for about 5 sec (with ignitor clicking entire time), then gas and ignitor shut off, blower continues for 10 seconds, then it cycles two more times, then shuts off. After that, the LED on the board blinks 3 times, indicating Ignition Lockout Fault. I have good gas flow and it's clear that the gas is igniting, as I get hot exhaust. I changed the control board because that seems to be a common fix and it's pretty easy (just not on the wallet). Unfortunately, that didn't do it. So I'm thinking the board is not getting the message that the gas is igniting, which leads to thermocouple. Anyone familiar pulling one of these out? Is the thermocouple built into the ignitor?

Model/year of the furnace? Some have separate heat sensor probes going to the circuit board, while the newer way just has the sparker, but it "reads" the flame magically, so your post is not clear on that. You changed the CB and it did not fix it, so is it the old way you can change the probe that lies alongside the sparker?That flame sensor probe ( if fitted) has its own wire that can be checked for connection too.

Braygor, Even if you don't want to change out the regulator, at least check that it is providing the 11"wc that it should. If it is at all old, get a 2 stage unit to replace it and many things will work better.Matt

Same thing happened with me, each year before we go south,but after 3 tries it stays on, I think that the igniter was damp/dirty, after it dried it worked.

BFL13 wrote:Model/year of the furnace? Some have separate heat sensor probes going to the circuit board, while the newer way just has the sparker, but it "reads" the flame magically, so your post is not clear on that. You changed the CB and it did not fix it, so is it the old way you can change the probe that lies alongside the sparker?That flame sensor probe ( if fitted) has its own wire that can be checked for connection too.Trailer is 2006, furnace is original. CB has four connections - the harness, one to the black cylinder (spark?) and two small lines, one red and one blue.

Atwood Furnace - Ignition Lockout Fault | Good Sam Community

17 Replies

doxiemom11
Explorer II
Oct 19, 2020
We had to change the circuit board when ours did that.
enblethen
Nomad
Oct 19, 2020
Check the alignment of the flame senor to insure it is directly in the flame.
Black should be ground
red goes to gas valve
white to limit switch
blue connects to the blue from limit switch that ties to the thermostat.
This is according to furnace manual I have.
Exact model of your furnace would help!
braygor
Explorer
Oct 19, 2020
BFL13 wrote:
Model/year of the furnace? Some have separate heat sensor probes going to the circuit board, while the newer way just has the sparker, but it "reads" the flame magically, so your post is not clear on that. You changed the CB and it did not fix it, so is it the old way you can change the probe that lies alongside the sparker?

That flame sensor probe ( if fitted) has its own wire that can be checked for connection too.

Trailer is 2006, furnace is original. CB has four connections - the harness, one to the black cylinder (spark?) and two small lines, one red and one blue.
A1B00902
Explorer
Oct 19, 2020
Same thing happened with me, each year before we go south,but after 3 tries it stays on, I think that the igniter was damp/dirty, after it dried it worked.
Matt_Colie
Explorer II
Oct 19, 2020
Braygor,

Even if you don't want to change out the regulator, at least check that it is providing the 11"wc that it should. If it is at all old, get a 2 stage unit to replace it and many things will work better.

Matt
newman_fulltime
Explorer II
Oct 18, 2020
Change your propane regulator
BFL13
Explorer II
Oct 18, 2020
Model/year of the furnace? Some have separate heat sensor probes going to the circuit board, while the newer way just has the sparker, but it "reads" the flame magically, so your post is not clear on that. You changed the CB and it did not fix it, so is it the old way you can change the probe that lies alongside the sparker?

That flame sensor probe ( if fitted) has its own wire that can be checked for connection too.

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Atwood Furnace - Ignition Lockout Fault

17 Replies

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