Replaced the thermostat. - Hi-Lo camper travel trailer forum

RichR · 07-21-2011, 03:05 PM

I finally got around to replacing the cheap Atwood thermostat with a Honeywell non-programmable digital thermostat from Walmart. The unit was $20.97, I believe.

Removing the old thermostat and mounting the new one was easy. I didn't use the supplied screws, rather I used two small wood screws and had to drill two small holes. It was then a matter of hooking the two wires to the Rc and Rh terminals and installing two batteries.

To run the furnace just move the side switch from off to heat and press the up or down buttons to select the desired temperature. You also get the benefit of having a digital thermometer.

You could also use the Hunter thermostat that Walmart sells but the Honeywell is a bit smaller.

I had one morning that was on the cool side and decided to throw on the furnace. It worked normally and didn't have the big temperature swings that the old thermostat had.

retiredcamper47 · 07-21-2011, 07:32 PM

I agree 100% with you Rich. The digital thermostats make a big difference compared to the original thermostats. They control the heat better. Like my wife said, "No more broken nails using the new thermostat."

Bob

RichR · 07-21-2011, 10:00 PM

Ha! Ha! I hadn't considered that benefit.

Richard · 07-22-2011, 10:49 PM

Hi guys, the digital thermostat is a great idea, but you need to closely monitor
your batteries, these stats are designed to be connected to a 24volt four or five wire system which provides power during normal operation. The batteries
should only provide backup power in case of power failure. I must tell you AC
service was not my favorite livelihood.

RichR · 07-23-2011, 07:48 AM

Good comment Richard. So far the batteries have been holding up by themselves, but an extra set in the drawer is always a good idea. One thing I like about the Honeywell thermostat is that it gives a low battery indication. I always keep backups for all the battery powered devices we have. If you have a handheld GPS unit never take it out on an expedition without spare batteries, otherwise it would only make a good paperweight and you could be very lost. Maps and compasses don't need batteries.

RichR · 12-17-2011, 01:03 PM

We went through the whole camping season with one set of batteries, but I noticed when I was removing them for the winter that the low battery indicator was flashing. I think the directions said that there is still 60 days of battery power left after the indicator starts to flash.

Norton Rider · 02-19-2013, 08:15 AM

Quote:

Originally Posted by RichR

It was then a matter of hooking the two wires to the Rc and Rh terminals and installing two batteries.

Rich,

I just got a Honeywell Thermostat. The R and Rc terminals have a jumper across them. Are you saying that you removed the jumper and connected the old wires to these terminals or did you connect one to R/Rc and the other one to another terminal. If so, do you remember which one?

Incidentally, I believe that the two furnace wires should be connected to the R/Rc terminal and the W terminal. Can somebody confirm this?

Raul

RichR · 02-19-2013, 01:22 PM

If I could have the trailer here to take a look it would be much easier to answer your question. I'm thinking one wire to either Rc or R and the other to C. if you could give me the model number I can look up the manual for it and figure it out.

Norton Rider · 02-19-2013, 03:55 PM

Quote:

Originally Posted by RichR

If I could have the trailer here to take a look it would be much easier to answer your question. I'm thinking one wire to either Rc or R and the other to C. if you could give me the model number I can look up the manual for it and figure it out.

Thanks, but the manual and the website are of no help. Neither states what each terminal does, they just provide the standard letter codes used for each terminal on different cooling and heating systems, i.e. R is equivalent to Rh... etc.

It should be easy enough to use a multimeter to figure out what circuits are closed when the temperature is lower than the thermostat setting. I just wanted to avoid a step.

RichR · 02-19-2013, 04:00 PM

The multimeter should do the trick, you just have to find the two terminals that go through the relay. Put the batteries in and adjust the temperature up and down to close and open the contacts.

retiredcamper47 · 02-19-2013, 06:29 PM

Norton Rider,

I have the Hunter Model 42995 digital non-programmable thermostat in my rig. Leave the jumper wire on. If you marked the wires with the terminal designation from the old thermostat, they should attach to the corresponding terminals on the Hunter. If I remember correctly (excuse me if I have a senior moment) there is is white wire and a red wire attaching to the thermostat. The red goes to the Rh terminal and the white goes to the W terminal. I would check mine to be sure but my trailer is in Butler being prepped for the upcoming camping season. According to my instructions the wire that attaches to the Rh terminal is the "Heat 24v or Millivolt Supply" wire. The wire that attaches to the W terminal is the "Heat Relay or Valve" wire. You will notice better heat control with the digital versus the manual thermostat.

Bob

JIM L · 02-19-2013, 07:25 PM

I purchased a honeywell non-programmable thermostat today for my HiLo. I put the batteries in and checked with my multimeter. Leave the jumper in place and connect one wire to the R or Rc screw and the other wire to W. The model I bought is RTHL111B Heat/Cool.

Norton Rider · 02-19-2013, 07:49 PM

Thanks everybody. This confirm what I thought: leave jumper in place, and use one of the R and the W terminal.

Raul

JoeJones · 05-09-2013, 06:30 PM

I bought stat on eBay and it has the same two bridged terminals and a note that the C contact is optional with batteries. I am electrically challenged-can you tell me where to connect the two wires???
Skyking

JoeJones · 05-10-2013, 05:07 PM

I just replaced the Atwood with the Honeywell that I bought on Ebay a week ago for $17 and ran one wire to the bridged conection and one to "w" and the furnance cranked right up and ran like a charm. Joe Jones

JoeJones · 05-10-2013, 05:09 PM

Quote:

Originally Posted by retiredcamper47

Norton Rider,

I have the Hunter Model 42995 digital non-programmable thermostat in my rig. Leave the jumper wire on. If you marked the wires with the terminal designation from the old thermostat, they should attach to the corresponding terminals on the Hunter. If I remember correctly (excuse me if I have a senior moment) there is is white wire and a red wire attaching to the thermostat. The red goes to the Rh terminal and the white goes to the W terminal. I would check mine to be sure but my trailer is in Butler being prepped for the upcoming camping season. According to my instructions the wire that attaches to the Rh terminal is the "Heat 24v or Millivolt Supply" wire. The wire that attaches to the W terminal is the "Heat Relay or Valve" wire. You will notice better heat control with the digital versus the manual thermostat.

Bob

Your directions are perfect!! Joe Jones

RichR · 05-10-2013, 05:26 PM

I finally looked at my thermostat and the red wire goes to Rh and the white to W. There is no jumper.

bengantt4 · 11-13-2014, 06:38 PM

I am Replacing mine with a Honeywell RTH221 Programmable. Question is do you leave the control for the fan on Auto or On?