Today the Dometic thermostat started reporting code E4, which means outdoor air temperature sensor fault. We don't have an outdoor temperature sensor. The heat and A/C still work. Our thermostat was replaced for this issue at the Rally last year, and we have camped for 3 to 4 weeks since then.. The Dometic heat pumps aren't a replacement for the furnace and only operate in temps down to about 40 (F). So either the thermostat has a different mode setting to operate the furnace, or if it's a combined mode, it's failing to switch from heat pump to furnace.
Follow these steps to perform a reset on your Dometic analog thermostat: Step 01: Set your Dometic analog thermostat to the "Off" position. Step 02: Turn off the power supply that provides electricity to your RV, including the thermostat. Step 03: Wait for a minimum of 30 seconds before restoring the power supply. Step 04: After restarting.. Air conditioner thermostat is flashing E4 code with temperature. Its a fifth wheel rv. 2017 keystone montana 340bh. By chatting and providing. My Dometic thermostat is giving a code of E4. I cannot find that information in any of the booklets we received with our.