Furnace Blower

YOu may have an insect or two crawling around they can short out things.. Also control boards and thermostats both can fail.

Newmar used Suburban back then, probably the SF 35. Is the Wall Tstat display OFF completely or you do NOT have it in furnace mode and calling that OFF? You have 2 Zones and Zone 1 is the furnace for the RV. If you have the Bottom black switch of the Wall tstat OFF, then the problem will either be the Furnace board or the front AC control board. IF you have it on Zone 2 and the Zone 1 has the furnace set to run, then that is your problem. Verify both settings on Zone 1 and Zone 2 are set to OFF. Doug

Rgtopda wrote:
I thought circuit board also, figured the fan is being told to come on. I thought someone was going to ask what kind of furnace and I forgot to write it down this morning and iam now at work. Even with Thermostat off it could be the thermostat ?

Possible ......DC Power is present
But more likely circuit board. DC is ALWAYS present just waiting for a 'trigger' to make up circuit to start fan etc

Again----depends of brand/model of furnace whether it fan power is part of circuit board or a timed delay relay

I thought circuit board also, figured the fan is being told to come on. I thought someone was going to ask what kind of furnace and I forgot to write it down this morning and iam now at work. Even with Thermostat off it could be the thermostat ?

The fan switch on t-stat would be for the A/C Fan...

Furnace fan only gets power when t-stat calls for 'heat' and then triggers 'blower power' on furnace circuit board (or old timed delay relay at furnace)

Could be a bad t-stat (contacts shorting) or bad furnace circuit board (contacts/connections)

Which furnace Brand/Model do you have??

No it is not on.

I know the stat is off but is the fan switch "on"?