Dometic fridge not cooling

oldpastonian replied on 16/07/2019 12:26

Posted on 16/07/2019 12:26

I have a Dometic RMD 8551 fridge (with separate freezer) in my 5 year old Sterling. I can see there have been other posts about apparent issues with this model not cooling to food safe temperatures. In my case I don't think its worked properly from new and in ambient temperatures of 25 degrees C to 30 degrees C the fridge barely manages 10 degrees C, (and not much below that at all in cooler UK temperatures) although bizarrely the freezer easily maintains well below freezing and quickly freezes ice cubes.

I've always followed the standard advice (level, shaded from sun, limit door opening etc) and removed the ventilation vents and have just now fitted additional ventilation fans, none of which makes any difference. As far as i can tell it has been installed in accordance with Dometic instructions.Using gas makes no difference.

It's not safe to store perishable food at 10 degrees C plus and it's fortunate I have a compressor driven portable fridge I can use as well while here in Brittany on holiday.

I raised the issue with Dometic back in 2016, but they more or less dismissed the problems siting the same advice as I've mentioned earlier. They also said the normal operating temperature for the fridge is 7 degrees C, which to my mind makes it not fit for purpose anyway as I understand perishable foods need about 4-5 degrees C for safety.

Previous fridges used in the same pitch have always worked satisfactorily even freezing in the fridge compartment sometimes in higher ambient temperatures so I'm pretty much convinced there is potentially a design flaw (or manufacturing fault) with this model given the various forum discussions about it (and as I've experienced the issues since new).

Perhaps there is a blockage or narrow cooling tube and maybe related to a design or manufacturing flaw.

Is this issue familiar to any one else and if so any solutions please?

Miggs replied on 18/07/2019 12:10

Posted on 18/07/2019 12:10

The only time I have noticed this is when I mistakenly left the fridge on battery after traveling. I find the 12v performance next to useless.

Conversely, I often have to turn it right down when on mains supply or else the milk freezes!

Not sure which model, it's the one they fit to Unicorn 3 Cadiz.

Tinwheeler replied on 18/07/2019 12:49

Posted on 18/07/2019 12:49

The fridge will only work on 12v when your caravan is connected to the car with the engine running so, in the circumstances you describe, Miggs, there would have been no power to the fridge cooling element.

Miggs replied on 18/07/2019 14:11

Posted on 18/07/2019 12:49 by Tinwheeler

The fridge will only work on 12v when your caravan is connected to the car with the engine running so, in the circumstances you describe, Miggs, there would have been no power to the fridge cooling element.

Posted on 18/07/2019 14:11

That could go some way to explain why it didn't cool down very much!

embarassed

Dorset Diver replied on 18/07/2019 14:30

Posted on 16/07/2019 12:26 by oldpastonian

I have a Dometic RMD 8551 fridge (with separate freezer) in my 5 year old Sterling. I can see there have been other posts about apparent issues with this model not cooling to food safe temperatures. In my case I don't think its worked properly from new and in ambient temperatures of 25 degrees C to 30 degrees C the fridge barely manages 10 degrees C, (and not much below that at all in cooler UK temperatures) although bizarrely the freezer easily maintains well below freezing and quickly freezes ice cubes.

I've always followed the standard advice (level, shaded from sun, limit door opening etc) and removed the ventilation vents and have just now fitted additional ventilation fans, none of which makes any difference. As far as i can tell it has been installed in accordance with Dometic instructions.Using gas makes no difference.

It's not safe to store perishable food at 10 degrees C plus and it's fortunate I have a compressor driven portable fridge I can use as well while here in Brittany on holiday.

I raised the issue with Dometic back in 2016, but they more or less dismissed the problems siting the same advice as I've mentioned earlier. They also said the normal operating temperature for the fridge is 7 degrees C, which to my mind makes it not fit for purpose anyway as I understand perishable foods need about 4-5 degrees C for safety.

Previous fridges used in the same pitch have always worked satisfactorily even freezing in the fridge compartment sometimes in higher ambient temperatures so I'm pretty much convinced there is potentially a design flaw (or manufacturing fault) with this model given the various forum discussions about it (and as I've experienced the issues since new).

Perhaps there is a blockage or narrow cooling tube and maybe related to a design or manufacturing flaw.

Is this issue familiar to any one else and if so any solutions please?

Posted on 18/07/2019 14:30

oldpastonian, I have the same fridge / freezer in our Carthago Chic C-Line.  I agree with your figures regarding safety.  Current advice is 4-5 C for the fridge and -18 C for the freezer.  Our achieves this well even in very hot weather.  I have measured with different thermometers, at different times, and different conditions, using both mains and gas.  It will even substantially cool when running on 12v, something that others often say does not happen.  

JVB66 replied on 18/07/2019 14:38

Posted on 18/07/2019 14:30 by Dorset Diver

oldpastonian, I have the same fridge / freezer in our Carthago Chic C-Line.  I agree with your figures regarding safety.  Current advice is 4-5 C for the fridge and -18 C for the freezer.  Our achieves this well even in very hot weather.  I have measured with different thermometers, at different times, and different conditions, using both mains and gas.  It will even substantially cool when running on 12v, something that others often say does not happen.  

Posted on 18/07/2019 14:38

The OP is talking about a fridge in a caravan, the wiring in motor caravans is such that running on twelve volt while driving is different to running via the 13pin plug and sockets that connect via a modern "intelligent?" alternators fitted to cars,we do not have problems with our dometic fridge when on site and useing the caravan/or EHU supply

heddlo replied on 18/07/2019 15:39

Posted on 18/07/2019 15:39

Oldpastonian, our Dometic fridge has the same problem, as you say it seems a fairly common gripe!  Our latest caravan a 2017 model has same fridge as our previous van, the RMD 8551, and as long as we have the cooling temperature on maximum it does seem to work a little better although to be honest we have yet to try it in very hot weather but I feel the results would be as poor as before.  We gave up buying perishable food in France in 2017 as it was not safe to keep it.  Also we got the same disinterest from Dometic when we asked their opinion at the NEC same year, same script as you got.  Sorry it doesn’t help much but just so you know you are not alone with this problem. 

brue replied on 18/07/2019 15:46

Posted on 18/07/2019 15:46

After finding ours wasn't working on gas in a heatwave here last year we went through the small print in the manual. The fridge has got to be pre-cooled empty on a high setting for at least 24 hours. It mustn't be too full when in use and the door must be opened as little as possible. This applies to gas and ehu. It worked for us, hope it's of help to someone. smile

heddlo replied on 18/07/2019 15:55

Posted on 18/07/2019 15:55

Difficult for us as the caravan is in storage.  It does get cold after about 18 hours and seems to maintain temperature (average UK temps) if set on max.  We do use additional cooling blocks in fridge if temperature is very warm. 

brue replied on 18/07/2019 15:59

Posted on 18/07/2019 15:59

Yes, I suppose in the same situation it's best to cool it down empty on site. We had to do this in the end, losing a lot of food! But we got there finally.