# Dometic fridge /freezer RM7505



## rotorywing (Jul 19, 2010)

Hi all

I have Dometic fridge freezer, AES lll RM7505 installed in the motorhome, wondering if anyone would know how low the temp gets in the freezer section. mine seems to struggle to get below 'zero'. tried on gas and 230v. 



Martin


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## steco1958 (Mar 5, 2009)

Mine is superb, in fact as good if not better than my domestic freezer at home


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## Spacerunner (Mar 18, 2006)

Ours also is brilliant. We can keep frozen food in it for ever. In fact we use it to supplement our home freezer when not away.

In this weather it needs the optional vent covers to make it most efficient but still works well without.


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## tramp (May 25, 2005)

have you put seperate thermometers in the fridge and freezer bit to check the temps?
sounds like the freezer temp probe is bust, where in the country are you?

shouldnt be expensive or hard to repair , not that I fix them


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## clive1821 (Mar 27, 2010)

Hi I have only experience with the RM7200 series but its on the same principal, the ice box should get to around -17c and the fridge unit should be around 5 to 6c depending on the outside temp. I understand you have noticed your problem only on gas and mains? and is ok with the 12volt supply as you have not mentioned it, if it was only with the gas I would definatley look at the gas jet as they get blocked and only a very small flame comes from the burner, it should be a good flame and sounds like a bunson burner, if blocked it will only produce a cool ice box around -1c, would be a good idea to clean the funnel at the same time, the mains electric could also be the cause as well being a fauty element or indeed a loose connection on the mains supply, if they are both ok then its a coolant leek being the common denominator... just a guide and someone else will have a better understanding of your problem, but I would start looking at what I have mentioned...


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## pieterv (Feb 3, 2009)

Mine didn't work too well on gas, and only fairly well on electric.

I did the following:
1. cleaned the flue
2. replaced the gas burner jet
3. put the fridge upside down for a day to mix the cooling liquids.

This imporoved things considerably.

Pieter


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## RhinoInstalls (May 11, 2010)

Hi Martin

If the fridge is struggling on both Gas and 240volts it sounds like the cooler unit (big black thing at the back of the fridge) is having problems. 

Make sure there is enough air flow behind the fridge. eg no winter vents fitted, or in high temperatures they can struggle. 

In some cases Ive seen badly fitted vents at the back where the heat is collecting at the top of the fridge and not going out of the vents.

Phil


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## rotorywing (Jul 19, 2010)

I believe that I might have a circuit board problem

With 230v connected indication led's are normal but temp in Freezer is ambient temp. heater on circuit board does not seem to be getting 230v.

Deselect AES and then select gas, still nothing happening, I waited for 45 minutes.

Removed 230v supply cable, [disconnected under bed] and then gas system kicked in and chilled freezer to -8c. checked after 2 hours......temp was -4c !!! and the gas system seemed to dormant. still no caution light !

Looks like a visit to a specialist required.

Update
I have now removed the winter covers............and have 230v reconnected, shall see what the temp is in the morning.

Thank you lads, shall update you tomorra

Martin


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## rotorywing (Jul 19, 2010)

Damn thing doesn't want to work on gas or 230v now, must either be the coolant or the circuit board. I still get normal operating lights !!

Martin


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## rotorywing (Jul 19, 2010)

*Update*

Having removed the top indicator cover on the front of the Freezer, I could see straight thru to the vent and outside, The fridge/freezer has not been installed iaw manufacturers recommendations. This lack of sealing allows the flue gases to migrate into the living area. If I was to park with the vents into wind, the habitation area would soon fill up !!

Boy am I glad we always use the fridge on ehu.............Think I'll contact Highbridge to see what they say, they sold me the van and they are the only people who have done habitaion checks. Their answer should be interesting

Martin


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## jud (Aug 15, 2009)

*fridge*

:?: hi rotorywing. we where parked up next to a couple who had a chausson and the flue gas was coming in the van and it seamed very dangerous to us please get it looked at. we take 2months of bacon&sausages to Spain frozen and are still frozen at the end so there is something wrong with yours i'am afraid all the best jud


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## UncleNorm (May 1, 2005)

Hi Martin! Last Christmas, when we had snow and ice, we lost a lot of food that was in our freezer compartment because it all thawed out!! :evil: 

We did not have vent covers fitted. Apparently, the thermostat in the fridge compartment decided that the fridge was cold enough so cooling was not needed. Therefore the fridge turned off. And because the fridge was off, so was the freezer and everything thawed out!!

We've just put a load of food in the freezer again, but this time we have vent covers. So cold air should not be sucked in to give the false reading to the thermostat.

HTH


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## rotorywing (Jul 19, 2010)

Hi Norm / Jud

Seems to be a similar problem, I shall take the van to the local Dometic approved Engineer tomorrow and ask his advice. Could be the source of the problem.

I'm beginning to wonder if Chausson have any fridges installed correctly

Regards
martin


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## rotorywing (Jul 19, 2010)

Well ..............what a saga, so much for dometic engineers.

Having taken the van to an approved Dometic Engineer, who very kindly spoke to Dometic while I was there. They stated that the control panel circuit board was at fault, this was duly delivered over the xmas period and installed, seemed ok until the first frost and the freezer failed again. Dometic then suggested changing the second circuit board [there is only two boards !!]. This was duly changed last week and the freezer was plugged in and duly chilled, cycling between -11 and -16. Then the ambient temp dropped below zero and the fridge failed, the freezer temp warmed up to -4.

So it was suggested by the Dometic engineer that the unit should be removed and the thermistor replaced................more labour costs !!. The van is booked in for this next Monday.

Then whilst researching the Dometic web site, I thought that I would investigate the manual for a replacement freezer, ie RMD 8505 and this is what I found

Chapter 4.8.2 of the operating instructions state

"When ambient temperatures are lower than
+10°C and the refrigerator is exposed to
these temperatures for extended periods of
time, an even regulation of freezer temperature
cannot be guaranteed for system-related
reasons. This can cause the temperature
in the freezer to rise and the stored goods to
melt. "

So it seems that these super duper Dometic Fridge freezers do not like cold weather. The only way for it to function correctly is to have the heating constantly running in the habitation area. I believe that the statement 'system-related' is code for design fault.

Getting very fed up now, How do I reason with the approved Dometic engineer [who hasn't charged me yet for labour] that I believe that it has all been in vane.


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## pieterv (Feb 3, 2009)

A lot of normal house freezers work like that as well.ours is in the utility and when itt gets cold there, the fridge doesn't come on much, and the temperature in the freezers goes up, as that only gets cooled when the fridge thermostat switches on.


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## rotorywing (Jul 19, 2010)

Hi 
The trouble is the thing is not kicking back in !!!. Probably cos the fridge is cold enough. Due to there being only one thermister which is in the fridge


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## jud (Aug 15, 2009)

pieterv said:


> A lot of normal house freezers work like that as well.ours is in the utility and when itt gets cold there, the fridge doesn't come on much, and the temperature in the freezers goes up, as that only gets cooled when the fridge thermostat switches on.


 hi we bought a deep freezer for the shed and they said the warranty would be void because they are not designed out side the house these days something to do with the insulation so if you buy one for the garage keep quite.jud


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## cabby (May 14, 2005)

we had this problem with our fridge freezer in the motorhome over the cold weather in December, would not work on gas or elec.properly,
spoke to a mechanic, who asked if I had made sure the vent in the roof was clear. maybe yours does not have one but thought should mention it.working ok now.

cabby


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## jeffo (Jan 15, 2009)

put some winter covers on the outer vents, works fine.jeffo.


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## UncleNorm (May 1, 2005)

jeffo said:


> put some winter covers on the outer vents, works fine.jeffo.


Well said that man!! It's what I said earlier...

http://www.motorhomefacts.com/ftopicp-964473.html#964473

The winter covers can be expensive, namely £46 for ONE, because you have to buy the three-part set of frame, grid and cover. So I made my own by fastening a piece if aluminium to the inside of the lower grid/vent.

Oh, another thing, a lot of domestic fridge/freezers are NOT designed to go in OUTSIDE ROOMS, SHEDS or GARAGES. If the ambient temperature is so low, there is no need for the fridge to work, therefore the freezer doesn't work either. Big thaw!!


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## rotorywing (Jul 19, 2010)

Tried it with covers 'ON' and covers 'OFF', seems to have a mind of its own. The original CB on the back of the unit was replaced yesterday.

The thing definitely does not like the cold weather, only solution I can come up with is to have the heating on in the living area to spoof unit into believing its warm outside.

Geez, 

Martin


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