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?

Dorset Diver replied on 19/07/2019 11:09

Posted on 18/07/2019 14:38 by JVB66

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

Posted on 19/07/2019 11:09

You really need to read the thread again. 

The OP is saying that on both mains and gas the fridge is not cooling sufficiently; that is his problem.  I simply stated that ours work well on all three power sources.  

Regarding the 12v, the fridge in question will switch automatically from one power source to another.  Once the battery is receiving power from the alternator it will switch to 12v unless it is on mains.  Your comment about intelligent alternators is a red herring.  The MH has an intelligent alternator and the only difference between the MH and C/van is one has a 13 pin plug and socket and the other does not.   

BoleroBoy replied on 19/07/2019 22:28

Posted on 19/07/2019 22:28

agreed, our Dometic cools very well on gas or EHU (in all climates) and seems to work as well as DD's when on 12v...

i never pre cool the fridge prior to driving and we always arrive with a lovely cold fridge....


TonyBurton replied on 22/07/2019 15:55

Posted on 22/07/2019 15:55

If the treezer is OK and the fridge is not cold enough it may be worth checking the door seal. I had a new door fitted after I found I could poke a piece of cardboard between the rubber seal and the fridge.

oldpastonian replied on 23/07/2019 15:24

Posted on 23/07/2019 15:24

Thanks to all who have responded so far. To clarify I follow all the Dometic guidance (as cited by some respondents) and it makes no difference. 

I will check the seal though as per Tony Burton's suggestion, although I'm pretty sure it's OK.

As an update I managed to find online a Dometic service sheet relating to their fridges and this advises there is a problem with the circulation tubes being blocked if the cooling tube is much cooler than the boiler/heater tube and that is the case with my fridge when feeling the tubes at the rear. 

I'm therefore thinking it's a blockage which has happened at some point in the past although, given the fridge has struggled from day 1, I'm more inclined to a manufacturing or design fault.

It will have to be checked more thoroughly when back home!