Installing digital thermostat

[doughpat]

Hey everyone, at some point you may want to upgrade the stock mechanical thermostat to a digital one. They are much more accurate and turn on and off with a very tiny click instead of the mechanical twang of the spring. Also, they allow for a lower minimum temperature. I wanted to keep my trailer just above freezing, because I am not ready to winterize yet, but the existing mechanical thermostat would not allow me to go much below 50°. This digital one will drop all the way down to 40.

Just a couple of things you might want to know: you will need to get a thermostat that is battery powered, as no power is provided to the thermostat. Your best bet is probably the most basic thermostat money can buy! A single stage heat only digital thermostat. I bought mine for about $25 on Amazon. Honeywell.

Second, when you were installing it, the temptation is to think that the two wires are logically color-coded: they are not. The blue wire with the white stripe goes onto the R terminal of the thermostat. The solid blue wire goes onto the W terminal. If you get these backwards, the thermostat does not function properly as you would imagine!Attachment 1

[billrector]

Do you not have A/C?

[waninae39]

we did the same.
it only runs to heater

the ac in our sport 22fb does not have a remote ability

[doughpat]

Originally Posted by billrector

Do you not have A/C?

Correct, though even if I did have ac, it is controlled by a separate thermostat (I believe on the ac unit itself?)

[Msherw]

I've seen threads about changing the Atwood mechanical thermostat to a battery operated digital one. I can't figure out any advantage to this since our A/C is controlled by a panel stat and the heater is all that would be affected.

Is there some really good reason for making a change?

I really don't need a digital readout to know if the AS is comfortable or not. (Our clock has a digital thermometer in/out so I can see a temperature if needed.)

I still go with 'if it ain't broke don't fix it' motto. When our mechanical one breaks maybe I'll consider on.

[perryg114]

As stated above, the digital tstat is good for keeping the trailer from freezing. Also you get an accurate reading of what the temp is. If you are industrious, you can hook to your AC. Dometic seems to have tstat issues where the AC won't stay on when the temp gets below 80. Sometimes this is because the tstat is too close to the AC making it think it is way cooler than it is. I have had two units do this. You have the AC tstat all the way cool and it only runs maybe 50% of the time when temp.in trailer is below 80.

[A W Warn]

Originally Posted by Msherw

<<snip>>
Is there some really good reason for making a change?
<<snip>>

Yes! The reason is comfort.
A mechanical bimetal thermostat has a fairly large temperature difference between furnace on and off. It was about 10 degrees F in my Safari.
Since I changed to a digital thermostat there is a 1 to 2 degree F swing. When camping in cold weather, 40 and below, the interior of the trailer is far more comfortable.

[Wheelhouse]

This is great info - wanting to do the same thing in our Sport 16 where the thermostat is right next to your head when sleeping and the “BOING” the spring makes wakes us up all through the night. So annoying.

[doughpat]

Yes -- I had forgot to mention that the stock mechanical thermostat does make a terrible "twang"! Really jarring and the barely audible 'click' that we now enjoy always give me a tiny sense of satisfaction : )

[JayTheCPA]

For non-Bambi owners reading this, wiring color will apparently change over the years. Best bet is to verify which is the hot lead and which one is neutral via a voltage meter.

Also, FWIW, some digital thermostats will only display ambient temperature down to the lowest set point. Example: if the lowest 'On' temperature for the thermostat is 40* F and air is -10* F, the display will show 40* F. This is useful to know for those whom want to wait on engaging the furnace only when close to freezing. Also, this limitation gives false hopes of freeze avoidance if the gas happens to exhaust while somebody is out-and-about, returns to see 40* F, and thinks that things are still safe from damage.

Another feature of the digital thermostat is that it is generally possible to relax or tighten the On / Off range. IIRC, the common range is + / - 2*F from the set point.

One thing to check / adjust is what type of fuel and system the thermostat thinks it is using as that can effect how it behaves (example: cycles per hour).

[doughpat]

Interesting. Mine reads down to 32°, then just says low. Also, I don’t think there is a way to adjust the dead band. But to be fair it is a $15 thermostat :-)