Troubleshooting your Dometic thermostat can help resolve a number of issues that it may have. It should be the first thing to try before calling service since in some instances the problems are not that complicated. They would quickly clear after performing simple troubleshooting procedures. In the following guide, we have given the various steps for troubleshooting common problems with these thermostats, as well as how to perform various operations.
How Do I Reset My Dometic RV Thermostat?
To reset the thermostat:
- Make sure the Single Zone LCD thermostat is in the Off Position.
- Press the “+” button and, while holding it, also press and hold the On/Off Mode button for 3 seconds. The LCD will show –, press the On/Off Mode again to turn system off. This completes the system initialization.
How Do I Reset My Dometic 5 Button Thermostat?
- Turn the switch off.
- Now at the same time press both the mode and zone buttons while turning the switch back to ON.
- The letters FF should appear in the digital display as you are doing that, and will remain there until you release both the zone and mode buttons.
- Hold the zone and mode buttons until these letters appear, then release the buttons when they do. Your system should be reset and ready to work.
All Dometic Thermostat Error Codes and Their Meaning
Dometic thermostat displays various codes to indicate the status or an issue with the system. The following are the various error codes and what they mean:
- E1- Loss of communication between the thermostat and all system power module boards. System will shut up.
- E1- Loss of communication between the thermostat and an individual system power module board. The LED will display will display error code “E1” and the zone number that lost communication. Any additional zones that lose communication will blink in addition to the current zone.
- E2- Open circuit or out-of-range Indoor Temperature Sensor. All heat and cool operation will be locked out. Manual fan operation will continue.
- E3- Shorted Indoor Temperature Sensor. All heat and cool operation will be locked out. Manual fan operation will continue.
- E4- Open circuit or out-of-range Outdoor Temperature Sensor (select models). Heat pump operation will be locked out. Air conditioner, furnace, heat strip, and fan operation will continue to operate.
- E5- Open circuit or out-of-range Freeze Sensor. Air conditioner operation will be locked out. Heat pump, furnace, heat strip, and fan operation can continue to operate but displays the last temperature set-point.
- E7- Loss of 120 Vac power to all power module boards on the system. The system will shut down.
- E8- Invalid zone configuration. The heat pump and heat strip DIP switches are both set to the ON position in one zone. Heat pump, heat strip and air conditioner operation will be locked out in the affected zone.
- E9- Invalid zone configuration. The dehumidifier DIP switch and either the heat pump or heat strip DIP switches are set to the ON position in one zone. Heat pump, heat strip, and air conditioner operation will be locked out in the affected zone.
Dometic Dual Zone Thermostat Common Problems and Their Fixes
E1 error code
This code indicates that there is a lack of communication between the CCC 2 thermostat and the power module boards or an individual power board module. The code should contain the zone that has lost communication and that information should appear on the display. If an additional zone has lost contact it will appear blinking next to the original code.
To fix this problem, the first solution option to try is to perform the system reset protocol. If that does not fix the issue, then you have to trace the cable from the thermostat to the rooftop AC. Check both connections to make sure they are tight and once you unplug the cable, you will have to do a system reset.
The issue may also be a component in the system somewhere that has failed and the best thing to do in that case is to replace the thermostat.
Buttons not working
If the buttons on your Dometic dual zone thermostat seem not to work, this may be caused by too much dust which has accumulated inside the thermostat or on the buttons.
To fix this problem, remove the cover and start cleaning the switches. Then pry off the buttons using a tiny screwdriver so you can see the contact points. Clean those with a contact cleaning solution and some Q tips.
Thermostat won’t stay on or turn on
The first place to look will be your ON/OFF switch. If the solder making the connection is cracked or broken, then no power will be sent to the switch.
Also, check all the other solder joints to make sure they are not cracked or broken. To fix this problem, simply take a soldering iron and solder and replace the old solder.
AC not cooling to the right temperature
To diagnose this problem take a reading with a handheld thermometer at different locations around the room before the AC comes on. Then take another reading at the same locations when the device turns off. There should only be a reading of +/- 3 degrees.
If the gap is larger then you should do a system reset to get the thermostat to operate
Common Dometic Analog Thermostat Problems and How to Fix Them
A wiring problem can sometimes be the reason your thermostat is not working or doesn’t work as it should.
To troubleshoot this problem, start by taking a voltmeter and checking if the thermostat is receiving any power at all. If there is no current flowing into the device then this likely points to a problem with the wiring.
You will need to establish where the wiring might be damaged by using a voltmeter or tester. If you are a DIY guy you can then fix on your own, but if not, have the wires fixed by a professional.
AC or heat is non-responsive
If your AC or heat will not turn on or not turn off, this might indicate that there is an issue with your thermostat.
For an analog thermostat move the slider well past the current temperature in the direction you want the temperature to go. If you do not hear an audible “click” then it is likely your thermostat is the problem. The “click” is a relay closing sending a signal to your heater or AC that it is time to turn on. You should also hear a “click” when your room temperature has come to the correct temperature +/- one or two degrees Fahrenheit or there about.
If you hear a “click” sound it is possible your thermostat may not be the issue. You can continue troubleshooting your thermostat to confirm it is not the problem.
How Do I Reset My Dometic Comfort Control Thermostat?
Performing a system reset on your Dometic Comfort Control thermostat restores the factory default settings. In the event of system memory loss or dip switch setting change, the thermostat will require a system reset.
To do a system reset on a Dometic Comfort Control thermostat, follow these steps:
- Make sure the thermostat is in the OFF mode.
- Then, simultaneously press the MODE and ZONE buttons. The LCD will display “IniT” and all available zones.
- Release the MODE and ZONE buttons.
- Press the ON/OFF button to exit system set up.
How to Turn Dometic Comfort Control Thermostat ON/OFF
To turn ON Dometic Comfort Control Center (CCC 2) thermostat when the back light is OFF:
- First press any button to wake up the thermostat.
- Then press and release the ON/OFF button. The LCD will display the last programmed settings.
To turn OFF the CCC 2 thermostat:
- Press the ON/OFF button and release.
- Only the time of day will display when the thermostat is in the OFF condition.
How to Tell If Your RV Thermostat is Bad
There are several signs that you can look for to tell if your RV thermostat is not working properly or not working at all:
Temperature doesn’t match thermostat setting
If you notice that your thermostat setting is not matching up with the temperature of the room, this can be a sign that the thermostat is bad and it is not relaying the signal properly.
Start by checking if the temperature reading on the thermostat matches the temperature in the room. You will need a separate thermometer to check the room temperature.
If the readings are different then this will cause an issue. The air conditioner, for instance, won’t cool since it thinks it is already cool.
No display on the thermostat panel
A thermostat display a blank screen is another sign that the thermostat is bad. If you have a digital thermostat and the screen is not showing you anything then it is no wonder the temperatures have remained the same for a while.
Check this too: White Rodgers Thermostat How-to & Troubleshooting Guide
AC or heat is non-responsive
Another sign that indicates there is an issue with the thermostat and that it may have gone bad is when the air conditioner or heat will not turn on or won’t turn off. On a digital thermostat, decrease or increase the temperature by at least 10 degrees past the current air temperature. You should hear a “click” from a relay closing, sending a signal to the AC or heater to turn on. If you don’t hear the click, then most likely your thermostat is the problem,