Furnace blower won't shut off...

BigBoy11 wrote:

Goostoff wrote:

BigBoy11 wrote:
Also, check to make sure thermostat is on Auto and not on Hi or Lo fan setiing.

For any system I have ever seen this setting is for the AC not the furnace.

For whatever reason, the Dometic thermostat on our 2012 Kodiak operates the fan the same for AC and furnace.

I will give the reasons.
1. You have NOT read the Dometic tstat instructions. If you do NOT have the instructions, then you can pass as at fault
2. The NEW style Dometic LCD tstats have a feature that other Dometic tstats do not have----- You can have the Roof AC fan operate in furnace mode if you set the Fan for the AC on Lo or Hi. If you do not want the roof AC fan to run on furnace mode, you set the Fan to AUTO.
3. There is only 1 brand/model of RV LP furnace(Atwood) that has a fan speed control(furnace has 2 fan speeds) and it is only installed on Hi line park models and hi line 5th wheel models due to cost and for this Furnace to function you can only use the supplied special Atwood tstat, for that furnace. Doug

Goostoff wrote:

BigBoy11 wrote:
Also, check to make sure thermostat is on Auto and not on Hi or Lo fan setiing.

For any system I have ever seen this setting is for the AC not the furnace.

For whatever reason, the Dometic thermostat on our 2012 Kodiak operates the fan the same for AC and furnace.

1. Hi limit switch stuck ON, This keeps the fan ON until the burner chamber cools down, if it sticks ON, then the fan will continue running.
2. The Board on your model has a built in fan relay and it may be stuck. Doug

The furnace is a Atwood model #8535- IV DCLP

There's plenty of gas in the tanks. The heater works its just that I have to manually turn the blower on and off outside the camper... It won't shut off on its own.

BigBoy11 wrote:
Also, check to make sure thermostat is on Auto and not on Hi or Lo fan setiing.

For any system I have ever seen this setting is for the AC not the furnace.

Moved from General RV'ing Issues forum.

Also, check to make sure thermostat is on Auto and not on Hi or Lo fan setiing.

Might be a dumb thing to check but if I run out of gas my furnace just keeps right on running until I turn on the other tank. athen I just turn the furnace off and back on again to trigger the ignitor.

Power to blower motor is hot up to timed delay relay. When t-stat makes up, power is sent to timed delay relay which allows power to motor.
T-stat shuts off....triggering power to timed delay relay should drop out shutting down blower motor after it has timed out.

SO........either:
Thermostat bad
Thermostat wires to furnace shorted
Timed Delay Relay bad (either a stand alone or one that is part of circuit board)

Take the thermostat top off. If it stops then you have your problem