Digital thermostat questions

[RMartin]

Hi all,
I need to replace our thermostat and would like to go digital. I am looking at the mach airxcel heat/cool unit. I’m looking for opinions from current users. With one degree accuracy I am concerned that units will cycle almost constantly. Is it that accurate and do you feel that your heat/cool units are being harmed at all? I would think Coleman would know what they are doing. Also, do you think the t-stat is durable or do you think there are better options available? I am considering the airxcel because I don’t have to fabricate a high/low fan switch,which brings up another question; Do you ever use low fan speed and if so, for what purpose?
Thanks,
Rob

[Marxk1]

I replaced the analog thermostat in my Eagle HT with a Coleman-Mach digital. Works great and takes the guess work out of selecting a temp setting. This was important for me since animals are in there even when I am not. The thermostat does not cause my a/c to cycle too quickly.

I use the low fan speed for heat cycles since a lower airflow does not give as bad a cooling sensation when the furnace first comes on and briefly blows cold air.

[TCNashville]

Many of us on here have made the switch to the Coleman Mach digital and no it doesn't seem to make anything cycle more or less. The swap is easy, wire to wire and I've had mine 4 years now with no problems. If running the A/C don't use the low fan speed because of potential icing of the unit.

[oldmanAZ]

Originally Posted by RMartin

Hi all,
I need to replace our thermostat and would like to go digital. I am looking at the mach airxcel heat/cool unit. I’m looking for opinions from current users. With one degree accuracy I am concerned that units will cycle almost constantly. Is it that accurate and do you feel that your heat/cool units are being harmed at all? I would think Coleman would know what they are doing. Also, do you think the t-stat is durable or do you think there are better options available? I am considering the airxcel because I don’t have to fabricate a high/low fan switch,which brings up another question; Do you ever use low fan speed and if so, for what purpose?
Thanks,
Rob

You didn't post what type of RV you have.

We replaced our OEM analog thermostat in our TT with a Coleman-Mach digital 3 years ago. LOVE IT! Does it hold to 1 degF? I don't know and don't care; the inside temp is now SO MUCH more stable (minimal high/low temp swings) that I don't bother to look at the temp once I've set it. YES it is ACCURATE compared to my indoor/outdoor thermometer. And, NO!, there is no reason to suspect the narrower temp range by using the digital thermostat is causing any kind of harm to the air cond or furnace. I don't feel any airflow difference on high or low, but there is an increase in noise using the high speed setting.

[diver6]

You can use any make of thermostat, I use a Honeywell digital from amazon that is programable and it works great. I just wired mine so I only have high fan I never use low, it only affects your AC. The furnace only has one speed.

[o2silverado]

Originally Posted by diver6

You can use any make of thermostat, I use a Honeywell digital from amazon that is programable and it works great. I just wired mine so I only have high fan I never use low, it only affects your AC. The furnace only has one speed.

That is true with the older styles. Most of the new style are using a 3 wire communication system and you can only use a compatible t-stat. You can no longer swap out a factory digital for any residential style stat with out a bunch of extra work !

[DNelson]

I added the Coleman digital thermostat and had constant problems with it resetting itself to its default 72 degrees. I read a thread here that said the problem was the thermostat power was wired to the heater and when the fan turned on it dropped the voltage enough to reset the thermostat. I called Coleman and they said a drop in voltage was the only thing that would cause a reset. So I rewired the thermostat to an unused 12 volt circuit on the power supply and installed a 15 amp fuse. I thought that would solve the problem but after needing the heater last week in south Texas I found out the thermostat was still resetting!

I went to Home Depot and bought a battery powered Honeywell thermostat for about $25 and wired it. Works perfectly! It is a higher quality thermostat than the more expensive Coleman one. The one issue and I am over it already is that it is white. Not sure if Honeywell even has a black model...oh well.

On a side note for our 2nd AC I installed this summer I used a LUX battery powered thermostat. It was only $18 and had a back lit display which the Honeywell doesn't have. Home Depot didn't have a LUX model.

[Atlee]

I made the switch to digital thermostat within a couple of months of purchasing my TT new. In all my earlier RV's, which didn't have ducted air, I used a cheap Honeywell to take care of business.

However, my latest TT came with ducted air. Because of that, I bought the more expensive Coleman-Mach digital thermostat. I did this because, it was a simply a case of switching wire for wire from the old to the new.

I haven't found it cycles that much more. I did find I could accurately set the temperature I want.

[Iraqvet05]

I tried a Honeywell thermostat in our old 26BH and installed a micro switch to retain the hi/low fan speeds. When I installed it, I got the wiring wrong and tripped the reset on furnace. It took me a few days to figure out my thermostat 12v POS feed came from the furnace so I didn't have A/C in the middle of the summer...ugh. I had to remove the couch to reset the breaker. I gave up on the Honeywell , removed it and installed a Coleman/Mach that worked great and the wiring colors were all matching.

[vegasguy]

There are different sizes thermostats out the. If you are going for a smaller one, pull you current one off the wall and see how big of a hole the factory put in the wall for the wires. One of my holes was huge. Didn't effect me because I wanted one the same as factory size, but if I tried to go smaller it wouldn't have worked.

[norty1]

I swapped out both of mine shortly after purchase. 7 years and still cooking . Keeps the rig more constant temp and we always run the fan on low to keep the noise down. with the ac's. No short cycling noticed.

[RedHorse1]

We have 2 Coleman thermo’s and tho I can’t state absolutely they seem to have a +- of abt 2 deg F. Meaning it will cool to 2 deg lower than the setpoint and not come back on until abt 2 deg warmer. It may be +- 1 deg but it works well. Thermo does not cycle too often.

[fr8erfxr]

Hey all, I'm looking to replace both of my thermostats with Colemans. Which thermostats are you guys using for the 2nd air conditioner without heat?

Thanks

[Foretm]

Has anyone considered the digital Bluetooth models? I was looking at those and they are more of a portrait orientation vs landscape like the current models, but I like the ability to adjust them from t8he phone app.

Anyone have these and comment on their functionality?

[Duke4857]

I put in a Coleman last summer. I am very happy with it. It was a direct wire change in our 24 RKS, even the screw holes lined up.

[norty1]

Originally Posted by fr8erfxr

Hey all, I'm looking to replace both of my thermostats with Colemans. Which thermostats are you guys using for the 2nd air conditioner without heat?

Thanks

I just used the same one and left off the heat wires upstairs. Less expensive and you have a spare if needed.

[BrentB]

Originally Posted by RMartin

Hi all,
With one degree accuracy I am concerned that units will cycle almost constantly. Is it that accurate and do you feel that your heat/cool units are being harmed at all?
Thanks,
Rob

A 1 degree differential is great for personal comfort, but will cycle fairly often and will reduce equipment life in the long run as the start process is harder on the equipment than the run process.

I installed a thermostat that defaulted to .75 degrees and it cycled way too often. I was able to adjust it to 1.9 and am much happier with it.

More info here: https://www.rses.org/rsesjournal/bal...idevmid=348436

[putz]

I installed a Coleman blue tooth thermostat in place of the slide unit.
I have a 2019 Octane toy hauler.

This works great, using free iphone app (android also available). I can even see the temp in my trailer while driving down the road. I can turn on the furnace or ac (Gen running) or change the temp. Lay in bed and change the temp.

You just have to be careful in selecting the correct switch.
Match the part number on the back of the old switch.
Then be sure the new switch is the one (Propane) not furnace. If you have a heat strip that's a different switch. I was lucky, I tried to order the wrong switch, but it was out of stock because it was for a regular furnace.

If you have a decal for a solar panel cutout be careful lots of solar wire
near the switch. I just matched wires color for color. I also did not use the long screw supplied, because I did not want to put a hole in a wire, but small screws and nuts. I did not use the supplied wire nuts, to big. Just used small wire connectors, not the straight ones but clear plastic, put both wires together then crimp. Just in case, I disconnected all power (Battery/Elect) and used a flashlight.

If you do install the bluetooth when you set it up the unit will flash 3 numbers for you to put into your phone app. Use all the numbers in order,
example 445607. Then scroll your screen to the left to see if it is showing
the temp. I no longer use the the wall thermostat because if you do you have to reset the phone app. No big deal just click on reconnect. You do not need the numbers. Write the numbers down just in case.

The big thing about all controls is there location. Mine is in the slide out
in the kitchen on my toy hauler. When you get your unit to the temp inside
you want, compare it with the gauge temp gauge because the gauge could
be in a hot/cold spot. Write the temps down and just use that temp.

I did not include a picture because your wiring could have different colors.

I looked at a couple of new 2019, Pinnacles and noticed they have the bluetooth thermostat.

This was a necessary mod for me because I could not get to the thermostat when the slide was closed. Best $100+ money I spent.

[RMartin]

Thanks to everyone for the valuable information. I am going to install the coleman thermostat as soon as the spring thaw reveals where I parked the fiver.

[poohbear]

You can get a mounting plate at any hvac supply that will cover holes . I have used light switch plates in a pinch but drilling the hole pattern you have to take your time as they crack easy.