Demountable camper group

zildjian wrote:Any nearer Martin? I understand these compressor's are the best these days but own up to not understanding them properly

Dunno really. Checked all the connections and they're OK. Took the thermostat out and put it back in again as Waeco suggested the sensor might be in the wrong place. But it's not and can't be really in that it slides into a metal tube in the fridge wall. So now it's back on and I'll leave it overnight and see how we go. I think compressor fridges can be great but I've noticed that Waeco generally, and the CR110 in particular, come in for a lot of hammer on Australian forums. Extreme temperatures, either high or low, seem to cause them problems.

I can understand Australians not being happy. The Waeco upright fridges run their compressors almost continuously if the outside temperature is high 30s or into the 40s celcius. If you are used to an Engel chest fridge an upright Waeco is likely to be less efficient.

Re. the thermostat, you can probably test it with a digital multimeter set to show resistance. you should see it go from near zero resistance to infinite as you adjust the thermostat - the equivalent of when your house thermostat clicks because you've just adjusted it past the current temperature.

Presumably, once wired up, if you turn it around to the zero or off position it does turn the fridge off? That off position is at the far end of the thermostat's travel and you should feel a click (and have to apply some twisting force to get it there).

Steve.

The other factor with these compressor fridges is the size. The larger you get the more current they use and that can be a real problem. My fridge is 140 litres and will draw between 6 and 7 amps when the compressor is running. So if running 50% of the time (typical) then that is 3 amp hours; so overnight that is around 30 amps hours of drain.

My fridge runs the larger of the two compressors, the BD50. I think the smaller fridges that run the BD35 compressor are much more battery-friendly.

Steve.

This is really bugging me because this fridge worked perfectly for three years before these problems started and now it all seems to cock! Anyway this is where things are at this morning - left it on overnight with the thermostat at a mid-way setting and, as far as I know, the compressor and fan were running all night. Temperatures this morning were -20.6C in the freezer compartment (which is too low) and +9.3C in the fridge (which is too high and only 5 degrees below ambient). This fridge, like all of the Waeco CR range I think, only has cooling elements in the freezer - there are none dedicated to the fridge space - so theoretically the coolth just spills from the freezer into the fridge. The temperatures I measured this morning would seem to indicate a flaw in that idea!

Anyway, I turned the thermostat down a pip or two below the mid-way point where I'd left it overnight and the compressor turned off so that would seem to indicate the new thermostat is working. It's now just a case of waiting to see if it will cycle on and off as it should and if it will achieve and maintain appropriate temperatures. Pretty obviously, if it doesn't get cold enough in the fridge space then I can't expect the thermostat to function as it should.

Is the door seal working OK? Your temperatures suggest that the freezer is cold enough to cool the fridge, but for some reason it can't manage.

Toshbins wrote:Is the door seal working OK? Your temperatures suggest that the freezer is cold enough to cool the fridge, but for some reason it can't manage.

Yeah, I've checked the door seals and they look good. I'm just going to keep monitoring the temperatures in both and see what happens.

Sounds like the diagnosis is getting somewhere.

Good point about the door seal. I've got a friend in Nevada who has a compressor fridge that runs 100% of the time because the door is warped. I can't remember what brand that fridge is though. So in his case the seal probably appears fine, but because of the warping it doesn't actually seal. I guess the same could happen if the seal looks fine but the magnetic edge of the seal has failed so is not sticking it to the cabinet properly.

I haven't looked myself, but maybe it is possible to remove the plastic door of the freezer, then turn the thermostat down further and see if the temperatures equalise a bit. Though this is not a real solution.

This all points to cold loss through the door or door seal. Of the two options 1) that the seal on the freezer door (which isn't really sealed) has got better, and 2) that the fridge door or its seal has got worse, option 2 sounds much more likely. The thermostat is forcing the compressor to run to try to get the fridge down to the temperature set. But it is clearly needing the freezer to get far below the temperature it should in order for sufficient cold to leak across to the fridge compartment. Assuming that the insulation between the freezer and fridge compartments has not mysteriously increased, it implies the insulation of the fridge compartment has reduced so that cold is leaking out much quicker than it should.

So the door seal is a very likely possibility, but you have checked that, though it is worth another careful check.

Another thing I have just thought of, though it might be unlikely, is that the one thing that really compromises insulation is water. Is there any chance that water has leaked into the fridge insulation rendering it pretty much useless?

Steve.

sabconsulting wrote:Another thing I have just thought of, though it might be unlikely, is that the one thing that really compromises insulation is water. Is there any chance that water has leaked into the fridge insulation rendering it pretty much useless?

As you say it seems unlikely Steve but, at this point, I'm prepared to check anything. I'll go over all the fridge walls and see if I can find any cracks where water could get through. Thanks for your help.

Well, final update on my fridge saga. Temperature discrepancy is still there - with the thermostat turned up the freezer is down to -20C but the fridge will still not budge below +9. I've checked the walls and re-checked the door seal and still can't find anything but have concluded it's got to be the seal. There seems to be no other explanation. Ordered a new one from leisurespares.co.uk (good people) - not in stock but hopefully should have it by early next week. £26.68 inc del and VAT - not bad. Hope to be soon.

I've never tried it myself, but apparently the standard test for a door seal is to take a bank note,



...... insert it in between the fridge and the seal in various places (top, bottom, left, right) and with the door closed check there is some resistance when you pull the bank note out.

Steve.