To do a Dometic thermostat reset on the common Single Zone LCD model, first turn the thermostat off. Then press and hold the “+” (up) button and the “ON/OFF MODE” button at the same time until the display shows two dashes (“– –”), which takes a few seconds. Release both buttons, then press ON/OFF MODE once. That re-initializes the thermostat and clears most minor glitches. If you have a different Dometic control, the steps differ—so always confirm your exact model below before you start. A bad thermostat can turn a good RV trip into a sweaty, miserable one, and a reset is the fastest first fix.
When a broken thermostat ruins the trip
Picture it: you’re parked somewhere beautiful, the sun is out, and the inside of your RV is climbing toward sauna territory because the thermostat won’t respond. It’s hot, everyone’s cranky, and the controls aren’t doing anything. In cold weather it’s the reverse—you’re layered up and still shivering while the heat refuses to kick on.
A misbehaving Dometic thermostat usually shows up in a few ways: it won’t switch between heat and cool modes, it displays the wrong temperature, the buttons seem dead, or the AC and furnace won’t turn on or off when they should. The good news is that many of these are software hiccups, and a reset clears them without a service call.
How to do a Dometic thermostat reset (Single Zone LCD)
This initialization sequence is the official reset for the widely used Dometic Single Zone LCD thermostat. Follow it exactly:
- Turn the thermostat off. Use the ON/OFF MODE button so the system isn’t actively running.
- Press and hold “+” and “ON/OFF MODE” together. Hold both buttons at the same time for a few seconds.
- Wait for the dashes. The display will show “- -” to confirm the thermostat is re-initializing.
- Release the buttons. Let go once the dashes appear.
- Press ON/OFF MODE once. This completes the reset. Now turn the thermostat back on and reselect your mode and temperature.
This same sequence is also used to initialize the thermostat after it loses power or after a control board is replaced, so it’s worth knowing.
The power-cycle reset (works on most models)
If you’re not sure which thermostat you have, or the button combo doesn’t apply, a power cycle is a safe, universal reset:
- Cut the power. Turn off the thermostat, then remove power to it—flip the RV’s main battery disconnect and unplug from shore power, or pull the fuse/breaker that feeds the thermostat and AC.
- Wait about 1 to 5 minutes. A short wait lets the system fully discharge and clear its memory. (Older advice to wait 30 minutes won’t hurt, but a few minutes is usually enough.)
- Restore power. Reconnect the battery or shore power, or replace the fuse/breaker.
- Turn it back on and reconfigure. Set your mode and temperature again and confirm it responds.
A note on multi-zone (CCC2) thermostats
Dometic’s multi-zone Comfort Control Center 2 (CCC2) uses a different procedure than the Single Zone LCD—it relies on MODE and ZONE button combinations rather than the “+” and ON/OFF MODE combo above. If your thermostat controls multiple zones, don’t use the single-zone steps. Check the label or manual for your specific model, or use the universal power-cycle method, which is safe across models.
Frequently Asked Questions
What buttons reset a Dometic Single Zone LCD thermostat?
With the thermostat off, hold the “+” (up) button and the ON/OFF MODE button together until the display shows “- -”, then release and press ON/OFF MODE once.
Why isn’t my thermostat turning on?
First confirm it has power—check the battery disconnect, shore power, and the fuse or breaker feeding it. If it still won’t respond, a reset (button combo or power cycle) often clears the fault.
How often should I reset it?
Only when there’s an actual problem, like frozen controls or wrong readings. Routine resets aren’t needed, and frequent glitches point to a deeper issue worth inspecting.
What if the reset doesn’t work?
If resetting doesn’t fix it, the problem may be wiring, a failed control board, or the AC/furnace itself. Consult a qualified RV technician to diagnose it.
Author: Ralph P. Sita
Ralph P. Sita is a seasoned professional with deep roots in both the HVAC and tech industries. His family’s business, Ralph P. Sita, Inc., is a locally owned and operated HVAC contractor with over 42 years of experience, serving the DC, Maryland, and Virginia areas. The company specializes in residential, commercial, and industrial heating, ventilation, and air conditioning services, offering everything from installation and maintenance to custom ductwork and indoor air quality solutions -www.ralphpsita.com. A former CPA, he spent the last decade as co-founder and co-CEO at Cybrary, a leading platform for cybersecurity and IT training. Cybrary became the largest, most well-known cybersecurity training businesses in the industry under his leadership. Smart AC Solutions is an opportunity to give back to the HVAC community by providing reliable, actionable information on all things heating and cooling.