Fridge not cooling down in hot weather

As a veteran of southern France when it can get up to 35 deg. plus we have certainly experienced similar problems withour Bailey and other vans.  There are basic limitations with absorption type fridges (rather than compressor type) but I must say that the Thetford on our newish motorhome works perfectly in temperatures in excess of mid-thirties so the latest designs have improved enormously. 

Fitting fridge fans helps a bit and that is something you can do yourself if you are practical.  There have been instructions on this forum and elsewhere - I used two computer fans salvaged from old computers.

We have a fridge thermometer and used to find getting into the green area (about 10 deg. C I think) could be problematic. Gas is more efficient but you will get through a fair amount if you use permanently.

During the handover on our new van, the technician told us when the weather is hot and the fridge is struggling, the answer is to turn the fridge dial down. Whilst this seems counter intuitive he assured us it works!

Wont make a blind bit of difference, it’s a thermostat and is either on or off. 

The thermostat will remain unsatsified until the box reaches a certain temperature when it will open and cut power to the heating element (or close the gas valve)

Turning the thermostat to a lower temperature will not increase duty, all it will do is remain unsatisfied to a lower set point. 

Absorption refrigerators as opposed to Freon compressor systems, use ammonia solution which isn’t particularly efficient when the temperature differential is reduced across the condenser as seen with hot ambient temperatures. Fans across the condenser help shift heat and allow that differential to open and create better conditions for the gas to exchange heat.

fridges should run about 4-5 deg's. stops bacteria build up, unless only used as a drinks fridge and not a salad one.

Hi

we have a Bailey caravan and experienced the same situation with our fridge, On advice of both dealer and Bailey, when it’s hot: we start the fridge on gas and then turn over to electric once cool.  To test put a cup of water in freezer and when frozen you’re good to go electric

Yes, there is more power in the gas flame than the mains heating element, just as there is greater power when on mains compared to 12V

Be aware though that absorption fridges are designed to maintain temperature and are not blast chillers. Where possible, always run them with a full box of already chilled/frozen items. Don’t expect them to pull ambient products down terribly well, they are not designed for that.

1-5C is the ‘official’ cold chain limits for dairy & meat

below -18C for frozen and above 70C for hot served foods

Our Dometic fridge has been troublesome from new. The manufacturers insist that it needs servicing annually. The tell us that it should achieve a 15 deg temp reduction from the outside temperature. Hmmm that’s down to 10 deg when the outside temp is 25deg. Advice to remove the fly screens from the vents and to fit auxillary fans has been fruitless. The dealer can’t find anything wrong. So at considerable expense we had a new refrigeration unit fitted (it comes as one piece). The current heatwave has been spent on our garden project, so it’s not been tried out yet. We never had these problems with Thetford units.

I had my van serviced recently and the person doing the service told me he had been on a course at the Dometic factory. There he was told that on some models Bailey designers had ignored fitting instructions which meant the fridges would never work properly.

The top vent outside the van should be level or above the top of the fridge or the air doesn't circulate properly. After fitting tall fridges they had only put them halfway up. On some vans they put the fridge on the nearside next to the van door. If you open the door and hook it back it partly covers the vents. Also if you have an awning the vents will be inside it. 

This is only what he told me but I have no reason to doubt it.

That makes sense. The heat comes directly out of the back of the fridge and the vents create a chimney effect with the hot air rising to the upper vent which needs to be nice and high. Fitting an extract fan at the top should help in that situation.

Despite all the adverse (and justified) general statements about absorption fridges, I can only repeat my previous comment that Thetford seems to have solved it. Ours works fine in ambients of 35 degrees so it’s clearly possible. Maybe it’s a combination of Thetford plus how Autosleeper’s have fitted it.