Dometic Thermostat E4 Error Message

[BeachBaby]

Has anyone experienced an error message on their Dometic Thermostat "E4"? We have a Mallard M335 (2018) and our AC/Heat has just stopped working. We are now getting this code. It is plugged into shore power. Neither the AC or Heat will come on even when adjusted temperature wise.


After scrolling through previous posts we checked our relay box. It is a miracle that our RV didn't catch fire. The relay box is fried!!! I have no idea what would cause this....

 

[danemayer]

E4 = Outside temperature sensor is out of range. If it's below 40 (F) outside and you are using the Heat Pump function, it's too cold for your heat pump to operate.

 

[carl.swoyer]

Dane,
That's actually funny!
It's so cold the heater won't work. I guess if the car won't start because it's too cold why not the heater.

Sent from my moto z3 using Tapatalk

 

[danemayer]

Dane,
That's actually funny!
It's so cold the heater won't work. I guess if the car won't start because it's too cold why not the heater.

Sent from my moto z3 using Tapatalk

Carl,

It seems to be a heat pump error message. 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. Without more info about the thermostat and Air Conditioner/Heat Pump/Furnace, it's hard to say.

 

[carl.swoyer]

Carl,

It seems to be a heat pump error message. 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. Without more info about the thermostat and Air Conditioner/Heat Pump/Furnace, it's hard to say.

It reminded me of trying to start my 68 vw in the cold winter's in NH. Crank crank crank .... Nothing.

Sent from my moto z3 using Tapatalk

 

[CoveredWagon]

I 've gotten this code a couple of times. I had the thermostat set in the wrong mode I believe, or some setting that was incorrect. Corrected settings and everything worked.