DOMETIC RV Air Conditioner Cool Furnace Thermostat User Guide
- June 9, 2024
- Dometic
Table of Contents
DOMETIC RV Air Conditioner Cool Furnace Thermostat
This process document
corresponds to the YouTube video Dometic RV Thermostat Basics. Please watch
this video for visual understanding of the process. If you are getting
started, some of the items shown are available on our Amazon storefront. If
this process is of value, we appreciate you starting your shopping from our
store. You can also support our efforts by using the THANKS button under the
YouTube video.
Turning the Thermostat on/off, display temp, switch between F/C
To turn the thermostat on, press the Mode button. To turn the thermostat off,
continue pressing the Mode button until “Off” appears on the screen. After 15
seconds of illumination, the screen turns off. With the thermostat off, press
either the Up or Down button to display the temperature. Simultaneously press
the Up and Down buttons to toggle the screen between °F and °C.
Setting the Fan Speed (Fan Mode)
Fan mode provides three speed settings:
- Low – Fan operates continuously at a low speed.
- High – Fan operates continuously at a high speed.
- Auto – Fan and compressor cycle on and off and the speed varies based on room temperature and temperature setting on the thermostat. When the temperature difference between the room and the thermostat is:
- >5 °F (-15 °C), the fan operates at a high speed
- <4 °F (-15.5 °C), the fan operates at low speed
To change the fan speed
- Press the Mode button until the Fan icon appears.
- Press the Up or Down button until the desired fan speed appears on the screen.
Setting the Temp
Press the Mode button until you see your desired mode on the screen. Press the Up and Down buttons until you reach your desired temperature setting.
Let’s go over a few basic use cases:
- Setting the A/C for overnight sleeping with continuous fan:
- Tap the Mode button to Fan and select Low
- Tap the Mode until Cool appears
- Tap the down arrow until 66 degrees appears The Low fan will remain on and the A/C compressor will cycle on until the temperature is at 66 degrees. The A/C compressor will turn off once the required temperature is reached. Be aware that it will go a few degrees below what is set before the compressor stops. However, the fan will remain on Low.
- Get the furnace going on a cool morning:
- Make sure your propane tank valve is open and that you have propane in the tank.
- Tap the Mode button to Fan and select Auto. Remember this means the overhead fan only comes on when the A/C compressor comes on, so with the furnace the overhead fan will remain off.
- Tap the Mode button twice to get to the Furnace
- Tap the up arrow to set the temp to 80 degrees Within a few seconds you should hear the furnace fan come on and then a clicking sound before the furnace fires up. Notice that the overhead fan does not come on. Should you wish to run the overhead fan while the furnace is on, go to FAN and change the AUTO fan setting to Low or High.
- Leaving the A/C on while you are out on a warm day:
- Tap the Mode button to Fan, then select Auto using the up/down arrows.
- Tap the Mode button again to get to the Cool screen.
- Change the selected temp to 80 degrees The A/C compressor will cycle on when the trailer gets above 80 degrees and come on regularly to maintain this temp. This is ideal if you have a warm day and don’t want to let your trailer to get too hot.
- Setting the fan and furnace for sleeping during colder evenings:
- Tap Mode button to Fan and select Low using the up/down arrows.
- Tap Mode twice to get to the Furnace screen and set your minimum temp for overnight sleeping.
- I like it pretty cool, so we’ll have the furnace kick on when it hits 55 degrees.
The fan will come on Low and stay on. The furnace, however, will only come on
when the temp goes below 55 degrees. Make sure you don’t have anything in
front of the furnace overnight. Also, the furnace exhaust can be very hot
outside the trailer. Make sure you don’t have anything impeding the furnace
exhaust.
Error Code (to insert into description):
E1 – Loss of communication between CT thermostat and module board. LCD will
cycle be- tween E1 and previous mode setting. System will shut down.
E2 – Open circuit or out of range Indoor Temperature Sensor. Heating and
cooling operation will be locked out. Fan operation can continue to operate.
E3 – Shorted Indoor Temperature Sensor. Heating and cooling operation will be
locked out. Fan operation can continue to operate.
E4 – Open circuit or out of range Outdoor Temperature Sensor (select models).
Heat Pump operation will be locked out. Air Conditioner, Fan, and Furnace
operation can continue to operate.
E5 – Open Circuit or out of range Freeze Sensor. Air Conditioner mode of
operation will be locked out, but displays the last temperature set-point.