digital thermostat

[swimmer_spe]

I have a 20 year old trailer that has an old manual thermostat for the furnace. Can I just switch it out for a digital thermostat? I know I need to make sure it'll work with the number of wires currently at it.

[deltabravo]

I upgraded mine earlier this year with a Bluetooth T-Stat

There's also a non Non Bluetooth version

[sayoung]

opnspaces wrote:
Hey Dusty, could you expand on your post? What part of the post is because homes use 24v and RV's use 12v? Is it the jumper between RH and RC? I've always thought that was weird that they all use an external jumper and don't just connect them together internally.

The reason some tstats have separate Rc & Rh is some systems use separate transformers for furnace & condenser.

[Eric_Lisa]

opnspaces wrote:
Hey Dusty, could you expand on your post? What part of the post is because homes use 24v and RV's use 12v? Is it the jumper between RH and RC? I've always thought that was weird that they all use an external jumper and don't just connect them together internally.

Not Dusty, but taking a guess at the thinking.

Home thermostats are powered by a transformer located with the HVAC system. That transformer provides power to operate the thermostat (assuming it is a thermostat that requires power and not an old mechanical one). Thus more than two wires between the furnace and thermostat.

RV thermostats will have an on-board battery (a couple AAs) to provide power. On a furnace only configuration (no AC) the thermostat is a simple switch. Two wires. Connect them together and the furnace turns on. Very easy to wire.

FWIW, taking out the mechanical thermostat and putting in an electronic one was one of the best mods I did on my RV and on my home.

HTH,
-Eric

[philh]

swimmer_spe wrote:

philh wrote:
NOTE: Even fresh batteries don't like being below 20F. Went to the trailer to do a little bit of work today, thermostat was cold and wouldn't start up. Now have lithium batteries in it.

So, fresh batteries every spring?

These were brand new batteries. Thermostat was not happy with the voltage they put out in low 20F. I was able to warm them up enough to get the furnace started, but my next trip to the store, picked up lithium which do work well in the cold.

[prichardson]

No they should last a couple of years. Batteries don't like to power things when very cold.

[swimmer_spe]

philh wrote:
NOTE: Even fresh batteries don't like being below 20F. Went to the trailer to do a little bit of work today, thermostat was cold and wouldn't start up. Now have lithium batteries in it.

So, fresh batteries every spring?

[philh]

NOTE: Even fresh batteries don't like being below 20F. Went to the trailer to do a little bit of work today, thermostat was cold and wouldn't start up. Now have lithium batteries in it.

[swimmer_spe]

time2roll wrote:

swimmer_spe wrote:
Trailer has AC, but it is not controlled by the thermostat. If I could, I would....

Well you most likely can however it may require A/C replacement and pulling thermostat wires and furnace control wires.

I don't want it that bad. If it were simple, then yes...

[time2roll]

swimmer_spe wrote:
Trailer has AC, but it is not controlled by the thermostat. If I could, I would....

Well you most likely can however it may require A/C replacement and pulling thermostat wires and furnace control wires.

[swimmer_spe]

time2roll wrote:

swimmer_spe wrote:
I have a 20 year old trailer that has an old manual thermostat for the furnace. Can I just switch it out for a digital thermostat? I know I need to make sure it'll work with the number of wires currently at it.

No air conditioner?

Otherwise yes you can buy a battery powered heat only digital thermostat.

Trailer has AC, but it is not controlled by the thermostat. If I could, I would....

[time2roll]

swimmer_spe wrote:
I have a 20 year old trailer that has an old manual thermostat for the furnace. Can I just switch it out for a digital thermostat? I know I need to make sure it'll work with the number of wires currently at it.

No air conditioner?

Otherwise yes you can buy a battery powered heat only digital thermostat.

[Spridle]

I changed my mechanical heat only thermostat to a digital Honeywell heat only unit last month. the on/off switch on the one that came with the trailer was difficult to move and I finally broke it of trying to switch on the furnace.
I installed this one.
Honeywell digital thermostat, heat only, with on off switch

It was simple.
White wire to W
Red wire to R

[opnspaces]

Hey Dusty, could you expand on your post? What part of the post is because homes use 24v and RV's use 12v? Is it the jumper between RH and RC? I've always thought that was weird that they all use an external jumper and don't just connect them together internally.

[Dusty_R]

opnspaces wrote:
If it only controls the heater then you probably have only two wires to deal with. There is no high or low fan to worry about.

Make sure the thermostat you buy can use batteries like two AA or something.
Once you purchase your new thermostat pull the old one off the wall and count the wires. If there are only two wires this will work for you.

• Disconnect the two wires from the old T-Stat
• Drill the mounting holes for the new T-Stat
• On your new T-Stat the RC and RH wires will probably have a small jumper wire connecting them together
• Leave jumper alone and add one of the wires from your RV, It doesn't matter which wire just pick one
• Hook the other wire from the RV to the W terminal on the new T-Stat
• Mount T-Stat on the wall, put batteries in and test it.

It really is that simple. It will probably take you more time to drill the two holes and hang it on the wall than it takes to wire it up.

This is because home thermostat's operate on 24 volt AC and RV ones are 12 volt DC or battery.

Dusty