I have a 190 litre Dometic Fridge Freezer installed in my JB off-road caravan. It is 9 years old and has been remarkably reliable for all that time. On a recent trip, the red fault light came on and the compressor stopped. Leaving out all the dramas that event caused, the fridge was running on 12VDC at the time and when 240Vac was available and I switched from 12VDC to 240Vac, the fridge started working again. However, I then placed thermometers in the fridge and freezer to check on the reliability. The freezer was very adequate, i.e. getting down to -25 C, but the fridge was running between 3 and 8 C. In my view, 8 c is a bit too warm. According to Choice 0 to 4 should be acceptable with 3 C being an ideal setting. From the above info, I deduced that I had two issues:
1. The 12VDC line from the battery has too much resistance built up over time due to corrosion, dirt, poor contacts, etc. resulting in voltage drop sufficient for the fridge to refuse to go. That cause is being repaired.
2. The Fridge is too warm. There was a lot of dust accumulated in the condenser at the back of the fridge that has now been blown out and removed, but the fridge is still too warm.
Before I tackle the electronic controls or the thermistor, I thought it worth asking in this forum for useful experience about the same type of Dometic compressor fridge.
-- Edited by StewG on Monday 5th of October 2026 07:34:43 PM
-- Edited by StewG on Monday 5th of October 2026 09:04:55 PM
It's not straightforward to get an accurate reading of the temperature of a domestic fridge. I recently measured mine with a calibrated mercury thermometer (240V normal domestic fridge/freezer) and I observed fridge temperatures of -2C, +4C and +8C depending upon where in the fridge I placed the thermometer. The freezer is around -20C which is beyond the mercury thermometer but within the range of a CA thermocouple.
The major storage areas of a fridge should be below +5C, no debate.
The wine/salad areas may be up to +8C but that's it. If the fridge cannot achieve that something is wrong. Frankly a decent white at 8C is a travesty but we'll move on.
Because I'm a "Glass half full" man I'll guess your fridge has a combination of dust dirt in the cooling fins and a poor contact in the electrical supply.
Having said that: I have seen fridge/freezers which have lost their gas (or most of it) keep the freezer cold but let the fridge warm.
Fill a 2L milk container with water and put it into the freezer: if, after 24h (maybe a bit more), it's not solid ice your fridge is dying :(
Thanks for your comments, BBN2. You raised a possibility of low gas that I had previously discounted, so maybe my best bet is to see a Dometic service and repair centre to get an expert diagnosis.
