Dometic RMS fridge cooling issues (2 Viewers)

[Pollypenny]

So just bought a 2011 Apache 634 and getting to know it's foibles. Went away for the weekend with no EHU so needed to rely on the fridge on gas. Worked fine during the night but couldn't keep cool during the day. I've had this trouble with a previous much older fridge so is it simply a case that when on gas they can't keep cool when the weather is warm? Was only around 20 degrees (the weather) so not extreme and the fridge was facing West. Not sure when it was last serviced but hoping that this is all that's required or am I being too optimistic and just need to accept that on gas they are not up to coping with warm weather? Works amazing on EHU although also seemed poor when driving to site as arrived with the fridge temperature having increased.

 

[mitzimad]

you need to get the fridge cold before it goes onto 12v when driving we plug in at home 24 hours before we travel
it seems these fridges have a sweetspot on the temperature selection usually around midway if you had it on full this could be the problem

 

[Jimbohorlicks]

As a low cost but effective measure .Fit fans to the top of the fridge vents to draw cooler air in from outside( through the bottom vents) to cool the heat exchangers on the back of the fridge.
As a temporary measure when parked up you can take off your lower vent to allow more air through.

 

[jezport]

Ours have always stayed cold in +30⁰ I suggest you have had it serviced?

 

[Lenny HB]

On gas they work better than on mains.
You need to clean the chimney & replace the gas jet while you are at it also replace the thermal paste behind the fins inside the fridge.

^{_{Subscribers  do not see these advertisements}}

 

[headlight]

So just bought a 2011 Apache 634 and getting to know it's foibles. Went away for the weekend with no EHU so needed to rely on the fridge on gas. Worked fine during the night but couldn't keep cool during the day. I've had this trouble with a previous much older fridge so is it simply a case that when on gas they can't keep cool when the weather is warm? Was only around 20 degrees (the weather) so not extreme and the fridge was facing West. Not sure when it was last serviced but hoping that this is all that's required or am I being too optimistic and just need to accept that on gas they are not up to coping with warm weather? Works amazing on EHU although also seemed poor when driving to site as arrived with the fridge temperature having increased.

My 18 year old 3 way fridge works better on gas than mains electric.
Last year we had it working fine on gas in 38c temps.
As Lenny says get it serviced.

 

[Pollypenny]

you need to get the fridge cold before it goes onto 12v when driving we plug in at home 24 hours before we travel
it seems these fridges have a sweetspot on the temperature selection usually around midway if you had it on full this could be the problem

It had 24 hours plugged in at home so was lovely and cold before we set off, but was warm after an hour and a half driving to the site and then switching to gas. I did have it on the coldest setting so maybe should have set it lower, so will try this. Thank you.

 

[Pollypenny]

As a low cost but effective measure .Fit fans to the top of the fridge vents to draw cooler air in from outside( through the bottom vents) to cool the heat exchangers on the back of the fridge.
As a temporary measure when parked up you can take off your lower vent to allow more air through.

Thank you for this advice. I can't even figure out how to remove the vents atm and don't want to break the clips, but sounds like a sensible idea.

 

[Pollypenny]

Sounds like a full service is the best plan so will get onto that

 

[Diabalo]

Freeze a couple of large plastic milk cartons (with water) and stick them in when leaving home. Also the thermal paste may need replacing on the cooling fins which is an easy DIY job.

^{_{Subscribers  do not see these advertisements}}

 

[FrankNicklin]

We have never pre-cooled the fridge before travel, we cannot hook up at home. The cold food will bring the fridge temperature down and its the last thing we load on the MH before we leave. Make sure the fridge is on 12V when travelling ensures the coolness is maintained until we reach site.

 

[Pollypenny]

Freeze a couple of large plastic milk cartons (with water) and stick them in when leaving home. Also the thermal paste may need replacing on the cooling fins which is an easy DIY job.

I have a huge supply of ice packs so all good in that respect. Can you explain more about the thermal paste replacement or will a quick google lead me to how this is done? Also, would a professional service include that anyway?

 

[Diabalo]

https://www.motorhomefun.co.uk/forum/threads/3way-fridge-thermal-gel-replacement.225866/

Pollypenny Have a look at the link above, the fins are normally held in with a few screws, scrape of the old heatsink/thermal paste re-apply and refit fins. Plenty of paste on fleabay or amazon..

 

[mitzimad]

if it didnt stay cool on 12v you need to check its working on 12v

 

[Barriesimpson]

Mine is a Thetford 3 way, which automatically chooses the power source, and is brand new as it came with the van I just bought. So far, in temperatures of 30+ it is working very well on gas. We still have yet to plug the van into EHU so relying on gas and 12V when driving.

^{_{Subscribers  do not see these advertisements}}

 

[Pollypenny]

if it didnt stay cool on 12v you need to check its working on 12v

How can I check if that is working and does a professional service include checking how it works on 12v, 230v and gas do you know?

 

[Gaston aires]

On gas they work better than on mains.
You need to clean the chimney & replace the gas jet while you are at it also replace the thermal paste behind the fins inside the fridge.

Just did mine. Gas burner fault (collapsed) now works perfectly again. £74 on EBay plus an hour of my time.
Phil

 

[autorouter]

I'm not convinced that the thermal paste between the coolant pipes and the heatsink is relevant to this problem. The fridge works fine on 240V mains. It works less well on gas, and may work less well on 12V. The coolant pipe and heatsink are common to all three cooling methods, so if the thermal paste was failing it would be the same problem for all three heat sources.

I'd concentrate on getting the gas burner side of things working, including the solenoid, supply pipe, gas jet and flue exhaust flow.