Atwood forced air heater. Reset fixed it.

It’s not mounted. Part of a three wire harness. We’re traveling today. I’ll take a picture of it tomorrow when we get get home.

The symtoms acted like a stuck sail switch; fan started every time. I wasn’t outside to hear if there was clicking.

There is an LED on the board that never lit that I saw.

That breaker should be on the housing that also has the sail switch, so it may have been stuck and resetting the breaker jostled it enough to unstick.

If it is the first run of the season the blower motor (Major power sucker) may have some "Sticktion" (that is it is slow to start) Though if it started and ran for more than a few SECONDS (long enough for burner to fire) I'd not think that is the cause.

But after a Reset it may have loosened up enough to run like forever.

So I re read my thread and I may not have expressed my scenario very well.

The fan motor didn’t quit and not restart. Every time you turned the thermostat off then on the furnace would act like it was trying to light. Fan would run, no heat, shut off.

Rinse, repeat.

So if the breaker being tripped didn’t stop the motor, did resetting it reset something else?

Thanks gents. I’ll replace it for starters. I’ll measure the amps when I get a round tuit.

Hardly any time on the unit, but it is 13 years old. I replaced a bad 20A ac breaker last week, but it had LOTS of hours on it.

They had a bad batch of those circuit breakers- it may be failing, or the motor may be going, drawing too much current.

Big Katuna wrote:
05 vintage. Front heater ran a few minutes then shut off.

I removed cover to look around. Saw the reset rocker, did it, tried again, lit fine.

Wonder what caused it to latch off?

That is a manual 12 volt breaker reset switch. Short or momentary 12 volt amp overload caused it. If it happens again, I would replace it before attempting to trouble shoot the internal furnace 12 volt system. Doug