Domestic fridge flashing E1 code .

Since the frig seems to be working fine, I'd say all you need to do is clear the fault code.

i have heard (here on the Forum) that passing a small magnet in front of the switch will clear the code.

Disclaimer: I've never had an error code and have never had to clear one so let me know if it works.

Never heard of using a magnet to reset a fault code.....reset a Norcold Recall Box yes but not a fault code :H

Anyway.....
Normally an E1 code is a 'hardware fault in the gas operation system'-----problem with igniter or gas valve.

BUT if you are getting the E1 fault code when using AC and Gas operation it could be a faulty thermistor (temp sensing probe in food section clipped to fin)

Dometic Thermistor/ Conductor (3851059042)
To test the Dometic thermistor, disconnect it from the main (lower) circuit board and place the other end (sensor end) into a glass of ice water (mostly ice). After a few minutes you should be able to get a resistance reading of 7,000 to 10,000 ohms between the two terminals of the connector. If the resistance isn't close to those numbers, it is bad.

You can just replace the sensor tip if thermistor is bad
Dometic Snip-the-tip repair kit.......LINK