Mysterious on/off toggle for furnace in basement?

[kramperD]

We have an 08 3400. I had trouble earlier this week with furnace blower running on own with thermostat off. Getting in the shop in 2 weeks to check that out and take care of some other repairs.

But I just discovered an add-on toggle switch in the basement utility. Wondering what it went to, I follow the wires next door to the furnace. While purposely running the furnace I push the switch "off" and off goes the furnace. I hit the "on" and away it whirls.

Is it usual to have a switch for the furnace outside like that? Why would you need it? Could this be the answer to the mysterious blower going off and on, on its own? Could previous owner have put this toggle switch in so that it overrides the thermostat? Any advise? Ozz? Thanks, D

[kramperD]

Just talked to the boss about this.....she's got a good idea. She thinks maybe the toggle's there to turn the furnace on and off if doing a quick stay over. You only slide out the bed and don't have to open the living room slide to get to the furnace. Just hit the basement toggle and you've got heat! What do you think? Sorry, Newbie at this, maybe that's why it's there in the first place and you already knew this. D

[Mudchief]

Sounds like he did the MOD Ozz did to keep the furnace fan motor running to move air in the unit. Then the main thermostat will turn the furnace on when needed to supply heat.

[Ozz]

Yepper, someone has been busy in the Mod dept. I did as Dennis described, just to move some air around. They just stopped short with the switch mounting area. But it still troubles me that the furnace fan runs with the fuse pulled, they could have tapped power from another circuit, to further confuse people.
When I kick the bucket, I will be leaning over a cloud....or poking my head up from a Volcano... and laughing at the poor soul that will be trying to figure out my Montana.....

[Art-n-Marge]

What?! Ozz, you don't document your changes with revision controlled schematics, installation instructions or user guides that can be printed or published at a later time? When you look down I think the only thing you'll see is someone giving a one finger salute. That's when you zap them with the lightning. Mooahhahahaha...

Okay, back on topic, is it possible to contact the prior owner and find out why and how the switch was added? If it's not on fuse control, that can't be good. Is there at least an indication of On or Off?

I'll have to think about this some more. I am not understanding the benefit, yet. I have a "Fan only" mode on my thermostat that I thought does this. Is it not the same thing? Ozz, does your control panel not have a fan only mode?

[kramperD]

Art - There is an on/off toggle outside, but as far as the fan mode, I tried it on the thermostat and it didn't work. I think it's only for the AC? Still learning....D

[Ozz]

The furnace does not have that option, when you want air circulation inside, as at times it can be stuffy, or when the electric or propane heater is on, and you want that heat to blend with the air on the other end of the trailer, the switch is nice. I ran mine all the way to the furnace circuit board from the wall panel where the switches and slide controls are.

http://s112.photobucket.com/albums/n...trol%20switch/

[kdeiss]

on our 2002 2955 I can run Fan only