What Does E1 Code On Dometic Thermostat Mean: How to Fix It?

A Dometic thermostat is the source from where you can control the temperature on your Recreational vehicle, also known as RV. This thermostat connects to primary heating devices (Multiple). But sometimes, the power wires get disconnected from the controller, and an E1 error code shows up.

The E1 error code on a Dometic thermostat refers to the fact that somehow one or more power circuit panels have lost connections from the central controller. This error only shows up when there is a miscommunication between cables.

You may think that it’s a very technical term and you need a mechanic to fix this problem. But it is not that complex, and throughout the rest of this article, I will tell you how I resolved my RV’s Dometic thermostat E1 error.


What Does E1 Code On Dometic Thermostat Mean?

When a connection between the controller and the valve’s ending point is not detected, the Dometic thermostat blinks an E1 error code on its display. 

A Dometic thermostat connects with the RV’s heating device through the cables and other wires with connecting points. So, those connectors can get disconnected when you are driving on rough roads because of the bumps.

The E1 error code is there to alert you that the Dometic thermostat controller cannot find connection with one or more devices, and they need to be fixed to balance the temperature on your RV. Otherwise, there will be problems regarding temperature maintenance.

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What Are The Reasons For E1 Code On Dometic Thermostat On RV?

There can be many reasons for the E1 error code on a Dometic Thermostat. Sometimes it can be a software bug without any physical disconnects or damage. 

But mostly, it is technical terms. Some of the most common causes behind the E1 error code on a Dometic Thermostat are given below:

  • Damaged Internal/Vent Fans
  • Air Inlet Clogged/ Blocked
  • Cables Unplugged or Damaged
  • Position of the Valve was not detected

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How Do I Fix E1 Error Code On A Dometic Thermostat?

When it comes to an RV’s Dometic Thermostat E1 error, most owners run to a mechanic to fix it. But you don’t need to always go to an expert. Most of the time, you can fix it by yourself with some garage tools. 

Below I will be telling you some methods I used to fix my RV’s Dometic Thermostat E1 error code.

1. Replace Internal Vent Fans

A ventilation fan is crucial in temperature maintenance in an RV because it exhausts hot air. Vent fans can easily be damaged because mostly it’s unprotected. 

When a vent fan stops working, the thermostat fails to detect it and shows the E1 error code. Here is how I fixed my ventilation fan, and you can do it too:

  • Unscrew the Vent flange from the inside and disconnect the wiring.
  • Open the vent cover by unscrewing the bolts.
  • Go outside, unscrew all 16-20 screws (depending on your RV) and remove the fan.
  • Then, use a blade or heat gun if you have one to remove the sealant.
  • Buy a new vent fan. Good quality vent fan may cost around $200.
  • Clean the sealant on the roof with a cleaner spray and set the new vent fan. Install the screws back in their places.
  • Come inside and close the cover and reconnect the power cables. Put back the flange, and you are good to go.

2. Clear Block Air Inlet

The air inlet is the key to balancing an RV’s airflow and vehicle’s air-conditioning system. Because of too much air intake through the air inlet, it catches the dirt and other debris. 

As a result, it gets blocked, and then there is a sensor that measures the proper airflow.

So, when the airflow is inaccurate, it sends a signal to the Dometic thermostat, and the E1 error code appears. You can clean the clogged air inlet by following these:

  • Open the RV’s front hood and find the air-inlet using its manual because the position can vary upon different RVs. You can also google it.
  • Remove the front panel of the inlet and clean it with a hand and brush.
  • If it doesn’t clean properly, unscrew it, wash with only water, dry it properly, and then put it back.

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3. Reconnect or Fix Wires

Sometimes because of rough driving, the wires get removed from the heat maintenance device, and an E1 error code is displayed on the Dometic Thermostat. To fix the wiring problem, follow the instructions below:

  • First, check all the wiring that connects the heating devices to the Dometic thermostat. 
  • You will find one or more wires disconnected or damaged.
  • If the wires are disconnected, reconnect them and put tape around them to make them solid. If not, buy new cables and install them, which should not cost you much—installing wires by just removing the old ones.

4. Check The Valve Connections

Connectors (lego style) are between every valve and the Dometic thermostat. Those can be damaged or burned. Check them first, then replace them with the following:

  • Turn off the primary power source.
  • Open the cover and find which connector is damaged. But the wires and throw the connector.
  • But new connectors will cost you around $5, and you can install them by following the manual on the box.

How Can I Reset E1 Error Code On My Dometic Thermostat?

Sometimes the E1 error code is just a bug in the Dometic thermostat, and it has nothing to do with physical devices. And it can be reset by following the list below:

  • Restart the Dometic thermostat.
  • If it doesn’t work, open the front panel and remove and plug the power cables.
  • If that doesn’t work, restart the main power circuit breakers.

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Dometic Thermostat is a frequently used device that raises many questions, and I will reply to some of them from my experience.

How do I know If RV’s Dometic Thermostat E1 Code Is A Bug?

First, you must reset the Dometic thermostat by following the steps above. If it solves, then it was a bug. If not, then there is physical damage.

Is Dometic Thermostats and Furnace Thermostat The Same Thing On RV?

No. The furnace thermostat is for maintaining the furnace temperature, whereas the Dometic thermostat is for controlling the RVs internal heat.

Why is my RV hotter Than Usual?

Primary heating or air cooling devices and valves can malfunction. Check your Dometic thermostat. If it’s showing an E1 code, then it’s confirmed.

How Do I Find The Exact Source Of E1 Code On A Dometic Thermostat?

Some high-end thermostat shows which valve is not detected, but unfortunately, Dometic thermostat doesn’t. So, you will have to look for the source one by one.

Final Thoughts

RVs need a lot of air to maintain the temperature, and one air-conditioner cannot maintain the whole temperature alone, which is why other devices carry its temperature.

Because there are so many devices, one slight misconnection can cause a problem, and the Dometic thermostat will warn you instantly. However, you won’t notice it immediately, and it won’t damage anything fast, but it will put pressure on other devices. in the long term.

Most people don’t know what the E1 code means and go to a mechanic asap. But fortunately, almost every problem related to E1 on the Dometic thermostat is fixable alone. If you have any confusion, then you can re-read the article.

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