Brand new fridge not very cold

It isn't possible to say if your fridge is faulty or not, but at least you have your dealer on side in case it is..

Some points to note from my experience of caravan fridges over the years :- 

A caravan fridge on 12v whilst towing isn't going to work at full efficiency.

If the side of the caravan with the fridge on is in the afternoon sun, in hot weather they can sometimes struggle to chill down. I have always found van fridges to be at their best in a slight breeze, so in still hot weather, or indeed if the fridge vents are in an awning that will also reduce their efficiency. 

I would have also thought that running a fridge on gas when the fridge vents are in an awning, will result in a concentration of carbon monoxide within the awning if all the awning doors are zipped up... Best to keep it ventilated.

Hope this helps 

I would say that the fridge in the last two new caravans (2005 and 2012) were slow to reach temperature. I have always put them on a couple of days before the off whilst on EHU at home. Also noticed when doing this in near sub zero temperatures that they did bot seem to work until I also put caravan heating on low.

Never switch to 12 volt when towing as fridge rarely off for more than 5 hours and the insulation seems pretty good to me.

This doesn't sound right to me. We have a fairly new Thetford fridge in our Motorhome and it stays cold when the ambient is 35 deg. C. It also cools quickly from ambient. You have the readings so if your dealer doesnt act then I would try and talk to the manufacturer. Your warranty is with the dealer but the manufacturer should be able to advise you what you should expect.

Thanks for the advice all.

We have recorded the temperatures over time and given them to the dealer. It's annoying that we have traded up to a high end 'van and basics not functional.

I've since read that dometic RMD8551 is not brilliantly powerful at cooling but wonder if anyone else has experienced problems like this with the tall fridge freezer?

The thetford fridge in our challenger sport was super powerful but smaller...

Vents were inside awning with door zipped open. Cooling problems also experienced at night without awning and with vents on shaded side.

@Easy T

I would have expected our new fridge to stay cold for a couple of hours with doors shut as you state.

Given that we drove for 2.5 hours on 12 volt without opening door, and temp rose from 5 degs to 14 deg - suggests to me insulation problem. Would you agree? The dealer checked and the 12 volt system while on tow is functioning...

Thanks

Trev

Try testing the fridge 12 Volt when the car is running measure the volts at the back of the fridge (remove the vent at the bottom and you will find the wires the two thick wires in the plug the reading for dometic should be greater than 11.9 

mine was 11.3 and the fridge did not work the dealer fitted much bigger cables ans suddenly it worked on 12 Volts  a Swift problem

There is some information on the net around the changes to car alternators that could be an answer for your 12v issue.  Normally the alternator is constantly on, controlled by the vehicle management system.    Forgive the paraphrasing, I've since lost the webpages around this, but essentially the alternator stops sending power to the van as it is not required once the batteries have reached full charge.    This is fitted due to the increasing vehicle emission targets and they are generally fittedto newer vehicle to decrease their emission levels.  I guess towing is not considered by the car manufactures when squeezing the emission levels.  

I've  had exactly the same issue as you with a smaller fridge, and have fitted a computer fan with a switch in the top vent to help draw air over the rear of the fridge.  This has increased the efficiency, but on 12v it's not maintaining a low temp.  

doesnt fully solve your issue, but may help understand it.

Assuming you fridge similar to mine a 2017 Conqueror 570.

The 12 volt element is rated at 170w at 12 volts dc, so the current drain should be 14 amps minimum, not 12 volt. So you are not getting full power.

My fridge a 9331 model is very poor at cooling, especially in warm ambient temperatures, but fine when temperatures are cooler.

Having looked into things it looks to me like the fridge isn't installed correctly, Dometic say the gap behind the fridge between wall and fins should be 20 to 40mm, mine is around 70mm.

They also say the top vent should be above the fridge, mine is level with the top, so too low. Effectively both things reduce the cooling air flow, so efficiency.

Which explains why those who tour abroad a lot have found fitting a couple of circulating fans sort the issue.?

I think that the primary issue is that Dometic fridges aren't as good as the ones we are used to. We don't have your tower, but we do have an under counter model. It's been consistent in its inability to cool adequately, in warm weather, since new. En route we have removed the gauze insect screens from behind the vents, fitted twin fans to aid cooling and finally had an independent (from the dealer who recommended the above) report. It seems that Dometic fridges are known as less than ideal within the trade, but it's rarely admitted to because there's nothing that the workshops can do with the design which often gives worse results over time. Ours has. Dometic is a German company by the way.

Here's the expert's report;

With reference to the above fridge.
The fridge has been reported several times to the dealer within the warranty period but unfortunately the dealer is no longer in business and the warranty action has not been dealt with.
The fridge was not cooling efficiently and advice was given regarding the removal of the gauze and vents to allow better air circulation. This has had mixed results. The fridge was then fitted with cooling fans.
On inspection today the fridge, although a cooler day was in the morning around 4degrees but usually by the evening the temperature risers to 9degrees. The fans were circulating but upon testing the cooler unit temperature was found to be very hot, above normal at the top and warm at the lower unit area.
It is of my opinion that the cooler unit has failed/failing and is overheating due to lack of circulation and it will only be a matter of time before the fridge cooling efficiency stops working.

ive always given the fridge/freezer a boost before setting of on a trip by freezing 2x2 litre pop bottles of water at home and on arriving at caravan put one in freezer and one in fridge before connecting to car and turning on to battery. seems to work well.