Problem with Dometic Fridge/Freezer

[ColinC]

I wonder if anyone can pinpoint what might be causing a problem we are experiencing with our Dometic 7655L fridge/freezer. This is in a van purchased new last autumn and has been used on 3 main trips so far.

 

At easter we had no problem with it during 4 weeks in the south of France. In June when we were in the Pyrenees and Dordogne for 3 weeks when the weather was warm (upper 20's C) but not nearly as hot as we have known it in previous summers (only used aircon on one afternoon!) there was a great deal of water condensation in the fridge. This first became apparent parked on a sloping site for several days when we did not have enough chocks to get completely level. The tilt of the van caused water building up in the drip tray under the cooling fins to overflow into the fridge instead of draining onto the drain tube. The fridge had to be mopped out several times a day.

 

I consulted the manual on return and came to the conclusion that I might not have set the thermostat low enough. Last week in N Norfolk the weather was very warm and I tried the fridge on Max. The result was even greater quantities of condensation, particularly on the fridge ceiling. As well as having to mop out the fridge several times, water overflowed from the fridge and soaked the carpet. I have checked that the drain tube is clear.

 

The problem occurs irrespective of whether we are using gas or mains. Throughout all this the freezer seems to be operating OK, and food and drink in the fridge stays nice and cool. Never experienced anything like this in over 30 years of caravanning and motorhoming.

 

Any ideas?

 

Colin

[Peter Highe]

Does the door seal seal?

 

Peter

[ColinC]

Peter'

I did check that. As far as I can tell, yes it does.

 

Colin

[Peter Highe]

Colin

 

The only time I have seen this happen (on my home fridge freezer) is when the door has been left ajar. There has to be two things to cause condensation - a cold surface, which you have - and an abundant supply of moisture laden air. The only place the air can come from is outside the fridge. (unless you keep a warm blooded mammal in there!)

 

You say the water overflowed onto the carpet. If it did so with the door closed it suggests the seal wasn't watertight and therefore not airtight either.

 

Could you try taping the door shut as an experiment?

 

Peter

[Clive]

Are you sure you have not got the little tab that is used to keep the door slightly OPEN pulled out? (Its for use to keep the fridge aired when its not in use)

C.

 

[ColinC]

Thanks for the observations. Yes, I think I'm going to have to pay careful attention to the way the door seals next time we use it.

 

Colin

[mark w]

Hi

 

assume you have good ventilation from outside the van? I.E you do not have some of those vents that can be closed, also, some vans have too small vents, you may notice vans now have two large vents top and bottom, we had an air flow prob on our 2004 Hymer needed larger vents fitted, but this was to aid cooling in plus 30c.

 

As I think you have sussed, van must be level as possible, may I suggest calling Dometic with your serial number handy they may have a faulty batch.

 

Good luck.

 

mark

[enodreven]

Hi,

 

Our Dometic Fridge/Freezer has a small heater fitted that reduces the condensation which we should switch on when we are on hookup,

 

I mention it as if we leave it turned on when we are just on the leisure battery it flattens it in a very short time,

 

The switch is on the underside of the top control panel and is only accessible when the freezer door is open.

 

Not sure if its the same on your model but its got to be worth checking ?

 

If you have the same setup MAKE SURE you turn it off when you are not on an electric hookup as it draws about 1.5amp constant, which dose not take long to drain the battery

 

Also we have an automatic cooling fan fitted as standard which helps cool the condenser coils

 

Hope that helps

 

[Derek Uzzell]

Colin:

 

I thought that 2007 Rapido 9048dF motorhomes came equipped as standard with a Dometic RM-7655T "Tech Tower" fridge-freezer/oven combination, but perhaps that's for UK-market models only and yours has a Continental specification. Anyway, it probably doesn't matter...

 

My 2005-built Hobby has a Dometic RM-7651L fridge-freezer - the non-AES version of the RM-7655L - and I've never had condensation problems with it like yours (or, more accurately, my wife's never complained to me about any!)

 

The design of the door-catches on early Series-7 models (including mine) was flawed and this made door-closing difficult. But the catch mechanism was redesigned for 2006 so yours should be OK. As the difficulty was very apparent, if you can fully close the fridge door easily, and easily move the door-lock to the 'Travel' position (ie. so that the black dot shows), then that particular defect can be discounted.

 

My Hobby has Dometic's gigantic L500 exterior ventilation grilles top and bottom, but I believe Rapido uses the smaller L300 grilles that offer some 20% less surface area. Nevertheless, (assuming Rapido has installed the appliance properly!) I would expect L300 grilles to provide perfectly adequate airflow. Dometic manuals warn that anti-insect netting fitted to the back of the removable part of a grille can reduce the free cross-section by up to 50%. Again I don't think this will matter in your case, but for anyone who regularly hot-weather camps and thinks that their fridge's cooling performance is below par, it might be worth removing the netting from the grilles to improve air through-flow.

 

Not sure what Clive's "little tab" is all about, as this model of Dometic appliance has a two-position locking mechanism for the door-catch. In one position the door is held securely closed for when the vehicle is being driven: in the other position the door is held firmly ajar to allow air to enter the fridge when it's not in use and thus minimise the opportunity for mould to form. When the door is locked in the 'ventilation' position, there's no doubt that it's partially open as the gap is visibly evident.

 

Braunston's fridge-freezer must be a different model, as (to the best of my knowledge) all RM-76** appliances have their 'frame-heater' switch immediately to the left of the energy selection switch on the front-left of the control panel and there's no need to open the freezer door in order to operate the heater's switch. The heater is intended to evaporate any water droplets that may condense on the external metal frame of the freezer compartment during high temperature/high humidity weather. It has no effect whatsoever on the refrigerator part of the appliance.

 

As Braunston warns, the frame-heater (if switched on) will operate continuously even if the appliance is switched completely off (a bloody stupid idea in my view). In the case of a RM-75** appliance the heater draws 35W of 12V power (roughly 3A) and, if left on inadvertently, will eventually flatten the largest capacity leisure battery. There is a big red LED to indicate the heater is on, but it's still an irritating accident waiting to happen. I've never had cause to use the heater, but my wife doesn't normally keep things in the freezer compartment until we are on the final leg of our trips abroad and I guess this may prevent condensation forming on the freezer's framework.

 

Unless there is actually something wrong with your fridge's cooling system, then (as has already been suggested) it's likely to be that the fridge door, when shut, is not sealing properly. Check that the magnetic seal itself and its attachment to the door look OK, and that there's no play in the door-catch mechanism or at the door hinges. As there's no adjustment facility in the door-catch or hinge designs, that basically means "make sure the fixing screws are tight".

 

It's possible (one sincerely hopes not) that the fridge door is warped, preventing a tight seal being formed at its edge. Although it should be easy enough to check the contact between seal and fridge-face on the outer edge of the closed door, it will be harder to do so on the hinge side and top and bottom. If there's any doubt, try closing the door on strips of paper suitably positioned in the suspect areas and see whether the strips resist being pulled out. If they can be removed easily (or fall out!) then the seal is not making proper contact with the fridge-face.