What Is The E7 Code On a Dometic Thermostat? Fixing E7 Error

Error codes can cause you some grief, especially when you either do not understand them or know how to fix the problem. Almost every modern piece of electronic equipment now has error codes that need to be figured out and understood.

What is the E7 code on a Dometic thermostat? When you see this code, the system is telling you that all 120 AC power has been lost and the system cannot operate as it should. That loss of power is for all power modules connected to the system. Checking for a blown breaker is one way to fix this issue.

To learn more about the E7 error code and how to fix it just continue to read our article. It has the information you need to know about to not panic and handle the situation like a pro. Take a few minutes and familiarize yourself with the possible sources and solutions.

What Does E7 Mean On An Air Conditioner?


This article is about Dometic appliances or thermostats, not generic air conditioners. So the E7 code appearing on your Dometic air conditioner should have the same meaning as it does when it appears on the Dometic thermostat. There is a loss of power.

However, different companies use the same codes yet do not use the same meanings. By that, we mean that the E7 meaning for Dometic will not apply to air conditioners made by other companies.

For example, the E7 code on some air conditioning units will indicate a problem with the outdoor fan and you need to look for blockages, etc. on that part. Also, the E7 error code does not always indicate that there is an unfixable problem present in your system.

For Dometic products, it could mean that there was a power failure and power was not restored to that unit. Or that a fuse blew and cut the power, or that there is a short in the line and so on.

No matter where you get the E7 error code, you have to investigate first before calling the repairman. The simple fixes you can do and if it is not simple or you do not like working on electrical wiring, then call the repairman.

How do I Fix E7 Error On My Air Conditioner?


The repair depends on what is wrong with the unit or power supply. For example, if you had a blackout or power failure of some kind, one leg of the system may have received damage which is the reason one AC unit is working and the other shows the E7 error code.

Or, the breaker tripped outside on the pedestal and all you have to do is find the right breaker and flip it back on. Of course, you have to turn it fully off first before flipping it back on before the power is returned.

Check your fuses if neither of these sources is the problem. You could have blown a fuse that cuts the 120 AC power to your units. Then, if your AC units work when the generator is powering them, you will have to check your transfer switch.

If that part has dirty or bad connections, or loose wiring those may be the source of your problem. Simply shutting off the power, cleaning the connections, or tightening the wire(s) should correct the issue. Or the part needs replacing.

Don’t forget to check your 50 amp plug to see if anything is wrong with it. If so, take the necessary steps to clean, tighten wires, fix or replace them.

How do I Reset My Dometic Thermostat?


Before you check your manual, one simple way to do this is to simply unplug from all power supplies and battery disconnect. Wait a couple of minutes or up to 5 and then plug everything back in.

If that is not the problem, then you can follow what the manual says and start by pushing the up, down, and time buttons all at the same time, then follow the following steps.

  • Make sure the main power is switched on.
  • ​Make sure the power to the thermostat is switched on.
  • ​Make sure the thermostat mode looks like “”.
  • ​Now press and hold the mode and zone buttons until you see “iNit” on the display screen. When you do, release the buttons.
  • Next press the on and off buttons.

You should re-program the Dometic thermostat immediately after resetting it. That should help its longevity and keep it working. What you do not want taking place is for the thermostat to default to the wrong setting.

If it does do that, then it can overwork and take too much power. For other Dometic thermostat resetting instructions, just click this link. It will take you to our article on resetting different Dometic thermostats

Fixing a Dometic Thermostat That Refuses to Turn On


There may be times in our RV life where this situation arises. Thermostats have a 10 to 15-year lifespan so it is possible that they will not turn on for any number of reasons. To turn one on manually just follow these steps:

  • Make sure the main power is on.
  • Make sure the power to the thermostat is on.
  • Reset the thermostat’s circuit breaker.

The thermostat should come on with that procedure. However, if you do not have temperature control set the temperature level to a lower setting and wait 10 minutes. When that time frame is over, reset the temperature level to the operating setting.

If you still do not get temperature control, follow the reset instructions above or call a repairman.

Some Final Words

Error codes are there to help you identify the problem and shorten your search time. The key is understanding what each code refers to then take the appropriate action.

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