Chinook RV

The PO replaced the original roof AC with an Air V Carrier brand with manual controls. Doesn’t even have a heat strip from what I can tell.
They threw away the 4 button control box and placed a universal home type manual thermostat unit in it’s place. They utilized the same phone wire but used only two of the wires, the red and black.
According to the thermostat, the wires used are red and yellow.
I wouldn’t think color on the stat makes any difference, since they’re acting only as jumpers.
But I’d like to know if the red and black wires control the furnace. I’m wondering if they’re the correct ones.
I took the rig to an RV place today and he tried to start the furnace by jumping the stat and bypassing the control (Mercury).
It did not turn on even after one minute.

Thanks everyone for answering this question in the tank heater thread that I sort of hijacked.
Turns out the #6 position in the brown box fuse box was empty.
I will place a 20 amp fuse in there and report back here in this thread.

I bet I'm not the only one who is looking forward to see how the mystery turns out. At least the first troubleshooting step is cheap and easy.

Good idea on starting a new thread. If someone searched "furnace" the other thread would pop up, but they might see that it was about tank heating and not even click on it.

Yeah, also, when there are so many pages in a thread, it’s tough reading, at least for me. I’m guilty of passing on those unless I really need to know something vital.
Anyway, I installed a 20 amp fuse and the blower started right up, then the heat kicked in. I could smell the burn! It’s kind of loud though. It would definitely wake me up at night, but then again, I would only use it in very cold environments, so Inorobably wouldn’t mind if it keeps me warm.
The thermostat is an universal two wire one, and it goes down to 50*F. I wonder if the furnace will kick on if it gets below that, which it does here in WA.
I’m happy that it works now. Seems that all systems are go!

Nice to have simple fix like this.

The thermostat should be "on" when the temperature is below 50F. Isn't there an "OFF" switch on the thermostat that you can use to shut the furnace down no matter what is the temperature? If not, maybe that explains the missing fuse.

Does the thermostat have an on/off as well and the temp setting?

If not probably why the fuse was pulled.

No on/off, but I can probably switch the house batteries to “store”, and everything will be off, and yes, even the old Carbon Monoxide detector light and Propane leak detector light go off when I store it.
Doesn’t matter though, because I would only do that if I’m not in it. But then again, if it get that cold, I would probably want some automatic heat to keep things unfrozen even if I’m not in it.
I can hunt for a thermostat with an on/off feature on eBay if there are any.
I’m going to start looking at solar next.

Aha, no "off" could explain it as the people above me already said. I would think a basic thermostat like that with an "off" would be pretty inexpensive, even new. It would drive me nuts not to be able to just easily turn it off (without pulling a fuse).

I don't have my furnace in right now, but the way I tend to use one like that is just that in the morning (or when arriving back from an outing) I push the thermostat all the way to full and let 'er blast until it's good and toasty, then turn it off. Then fire up the Wave heater to keep things warm in peace and quiet and without using power.

I'd be awake all night with that thing going on and off, but I'm a light sleeper (and also I don't sleep with heat on anyway - I just use a good sleeping bag or comforter). In my campervan the thermostat was right above my pillow -- perfect! Stick an arm out, push it to 95º and let it blast it until it's warm enough to emerge and face the day

I just got in from a nice drive with the rig. Put the battery switch to “store” and then tried the furnace. No power, yay!
Problem solved. I love this Chinook!

A couple of points to consider:

1) With the Store switch on, you can't charge the house batteries from shore power or generator (say you have rig plugged in but no need to run furnace).

2) With the Store switch on living in the rig is a bit spartan (there may be times you want the furnace off, but you want to use other things).

3) I don't think you can run the refrigerator with the store switch on, even on propane. I say that because it requires a small amount of DC power for the boards, and I think that circuit may be cut off by the Store switch. If so you could re-wire, but then too a new thermostat is probably easier and will have an "off" setting. Basically any thermostat will work (oh there may be some fancy modern one that won't, but a basic one will).

The absorption refrigerators take their time to cool down, so I could envision a time you want to run it before or after a trip (you get home late, too lazy to unload), but maybe don't want the furnace to be able to come on.

The Store solution will obviously work. I don't think I'd like it long term, but that's me.

I just did a bit of poking around for cheap basic thermostats. Most of the heat only ones didn't have on/off switches, but a few did. OTOH, there were some ~$20 heat/cool ones that did have an on/off switch (off/heat/cool). I guess maybe they assume no-one wants a house below 50, so if heat-only they don't usually provide a switch? But I wonder if you could hook up one of the heat/cool ones with the switch and just ignore the cool part?

I also forget how many wires you'd want (they have various ones depending).

But just for a concept, $19 at Home Depot:



https://www.homedepot.com/p/Economy-Hea ... /100400017