# Thermostat Upgrade



## STBNCBN (Feb 7, 2007)

I got tired of setting up camp only to find the batteries dead (or too cold) in the remote. I decided to install a mechanical thermostat I found at a RV parts store for $19. I traced the two wires from the AC unit that control the furnace to the fridge access panel on the outside. I cut them and spliced in two new wires and ran them to the new thermostat. Now I can run the furnace and fan at the same time to eliminate cold spots in the trailer.









This shows where I poked the new wire through and into the sticky back conduit. This is at the furnace intake.









This shows the thermostat on the wall. This location seemed to be the best for optimum control.


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## ranier1315 (Jan 4, 2008)

Awesome! I'm gonna do this one. I like to dry camp and it always seemed like the "remote control" never shut the furnace off. It just rand and ran. Thanks for the pics.


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## Lady Di (Oct 28, 2005)

Do you still use the remote for ac?

Would LOVE a wired thermostat for the furnace.

The ac is fine as is.


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## ranier1315 (Jan 4, 2008)

Hey STBNCBN,
What color are the thermostat wires? I can prolly find them with a meter but if you already know it would save me some time.


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## Doxie-Doglover-Too (Jan 25, 2007)

ranier1315 said:


> Awesome! I'm gonna do this one. I like to dry camp and it always seemed like the "remote control" never shut the furnace off. It just rand and ran. Thanks for the pics.


that's what my furnace does, I WILL have this mod! woo hoo!


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## Oregon_Camper (Sep 13, 2004)

Doxie-Doglover-Too said:


> Awesome! I'm gonna do this one. I like to dry camp and it always seemed like the "remote control" never shut the furnace off. It just rand and ran. Thanks for the pics.


that's what my furnace does, I WILL have this mod! woo hoo!
[/quote]

You dry camp?


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## STBNCBN (Feb 7, 2007)

ranier1315 said:


> Hey STBNCBN,
> What color are the thermostat wires? I can prolly find them with a meter but if you already know it would save me some time.


Remove the inside cover to the AC unit. There should be two blue wires spliced to another set (probably a different color, in fact they may change a few times as you trace them). Trace these wires to a location convenient for cutting and splicing your new thermostat wires (mine was in the outside access for the fridge). Remember to cut in such a way you can reassemble if necessary. If you take the two wires and hold them together (you wont get shocked) the furnace should turn on, and when you separate the furnace turns off (if it is hot the fan may run for a few minutes). The new thermostat will control this contact. In my application I used speaker wire of the same size as the existing.

Once cut the two blue wires in the AC will do nothing, however I suggest taping or using a wire nuts. With the remote the AC will do nothing in Heat mode, but you can use all other functions. Others suggested using the dry function along with the furnace to control humidity, but I didn't notice any significant difference.

You will need a 12 V thermostat or RV thermostat. These don't require control power and are all mechanical. Home thermos will not work because they require AC control power. Another nice feature is you can control the temperature differential, meaning how many degrees below the set temperature do you want the thermo to turn on.

Background- From what I gather, the AC and furnace are two separate units, possibly made by different manufactures. The furnace does not have a brain (thermostat), it only has two wires that when touching turn the furnace on. The AC unit does have a brain, and when in Heat mode, it's using its brain to control the furnace. Having the heat on a mechanical thermo is much safer when camping in the cold. You don't have to rely on the electronics of the AC unit or the batteries in the remote. I will post more pictures in the next day or two.


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## Doxie-Doglover-Too (Jan 25, 2007)

Oregon_Camper said:


> Awesome! I'm gonna do this one. I like to dry camp and it always seemed like the "remote control" never shut the furnace off. It just rand and ran. Thanks for the pics.


that's what my furnace does, I WILL have this mod! woo hoo!
[/quote]

You dry camp?








[/quote]
yes, at my dad's USFS campground that he hosts. But dry or not, my furnace won't shut off unless of course I take it to the dealers and then it works fine


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## Oregon_Camper (Sep 13, 2004)

Doxie-Doglover-Too said:


> yes, at my dad's USFS campground that he hosts. But dry or not, my furnace won't shut off unless of course I take it to the dealers and then it works fine


Of course...just like cars when you hear that darn "click/clunk...click/clunk" then it's gone at dealer.


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## Thor (Apr 7, 2004)

Great idea









Too bad for me because I love my remote - I moved my to bed so I do not have to get out of bed to turn the heat on.









Thor


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## camping canuks (Jan 18, 2007)

STBNCBN said:


> I got tired of setting up camp only to find the batteries dead (or too cold) in the remote. I decided to install a mechanical thermostat I found at a RV parts store for $19. I traced the two wires from the AC unit that control the furnace to the fridge access panel on the outside. I cut them and spliced in two new wires and ran them to the new thermostat. Now I can run the furnace and fan at the same time to eliminate cold spots in the trailer.
> 
> 
> 
> ...


looks very nice, good job


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## kjdj (Sep 14, 2004)

The thermostat mod is a classic. I used a $20 Hunter electronic from Walmart. It runs on a 9volt battery and has a thermometer.
In cold weather when the trailer gets real humid you can run the furnace and A/C at the same time to dry thing out. 
By the way, the wall is very easy to fish a wire.


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## Oregon_Camper (Sep 13, 2004)

STBNCBN said:


>


Have you installed any type of stopper for the freezer door? Seems like after a summer for small bangs, the freezer door (or thermostat) might show some damage.


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