Really really annoying fridge fridge problem - any suggestions?

Rivers & creeks

Rivers & creeks

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We've got a Waeco CR80 fridge (with mini freezer compartment). It's great in marinas, works a treat and I didn't notice that it was on most of the time. But now that we're off grid I've noticed a very frustrating issue. It doesn't recognise that it's got to its target temperature! It stars up, works away for half an hour or so - we have it set not very cold - and then clicks off. Great you'd think but then it almost immmediately starts back on and works away for half an hour or so, clicks off and the starts back on again! I know that if the volts aren't high enough then it does the endless start up and off of the compressor but that isn't the issue here, it almost never switches off. Any suggestions? It's using vast quantities of electricity and we banked on it using its stated average of 1.5amps an hour average. It's in a well vented compartment with a computer fan extracting the warm air.

Any ideas would be very helpful.
 
Colvic Watson said:
We've got a Waeco CR80 fridge ...................It's using vast quantities of electricity and we banked on it using its stated average of 1.5amps an hour average.

Any ideas would be very helpful.
Click to expand...

If it's cooling below the expected temperature then it s very probably a faulty thermostat.

If its not cooling below the "set" temperature despite the time it is running then it probably needs regassing
 
I have no real experience on boat fridges. BUT I do have experience on some big huge fridges.

That sounds like one of two issues:
- some form of over running cut out kicks it off after a period of time and when it has reset it turns back on. (but its a dial thermo so not likely a programmed feature - so more like its faulting out)
- the huristics are set wrong on the thermostat. But if it was that you would expect it to drop temp say to 6C heat to 6.1C and switch back on, cool again the 6C and keep start stopping. What you want is for a 6C fridge to heat to 7C cool to 5C.

But its a cr@ppy dial setting so you wont be able to do much about it. Is it a new fridge? If so I'd be checking with the manufacturer - preferably with at least some max min temp readings but ideally a data log (This is a really simple bit of kit... http://www.ebay.co.uk/itm/USB-Tempe...der-32000-Point-Meter-CR2032-UK-/282027934988 worth about 5 times the price - cheaper may be available it was my first hit)

If its an old fridge and you are handy with a soldering iron... I'd replace it with the same thing below (can be configured to kick on at a temp or off at a temp and you can set huristics so that its not yo-yo-ing on and off all the time. )


One other thought? What is the air temp in the cabin? Below 15-16C you may find it mis-behaves. Try switching the PC fan off and see if it behaves better! In port you may be finding the cabin temp higher than underway. If so thermostat on that fan (like this? http://www.ebay.co.uk/itm/50-110-C-...-Control-Switch-DC-12V-CHIP-205-/371873576509) to switch fan on only when temp 20C ?
 
ShinyShoe said:
One other thought? What is the air temp in the cabin? Below 15-16C you may find it mis-behaves. Try switching the PC fan off and see if it behaves better! In port you may be finding the cabin temp higher than underway. If so thermostat on that fan (like this? http://www.ebay.co.uk/itm/50-110-C-...-Control-Switch-DC-12V-CHIP-205-/371873576509) to switch fan on only when temp 20C ?
Click to expand...

Thanks for this and the other replies - yes cabin temp is usually below that, why does low cabin temp cause problems? I've been trying to keep the back cool - have I been keeping it too cool? I never imagined that was possible!
 
Colvic Watson said:
Thanks for this and the other replies - yes cabin temp is usually below that, why does low cabin temp cause problems? I've been trying to keep the back cool - have I been keeping it too cool? I never imagined that was possible!
Click to expand...

the ambient temp makes a huge difference, its using ambient air to cool the compressor.
we had similar symptoms to you. Paul sorted it. extracted the old banned gas & recharged with new eco friendly stuff. we now have cold bier & make ice cubes

Oh i also added a computer fan to the compressor locker to extract air at high level
 
Last edited:
I don't know why - but this thread makes mention of it...

http://forums.outandaboutlive.co.uk...of-Waeco-CR80-fridge-freezer-electric-/30501/

For your model.

I'm not sure I understand the physics but the compressor seems to struggle to recompress the gas into liquid when it is colder.

I've been doing some work on WiFi thermometers over the last few days testing battery strength, WiFi Strength and such like. I can go from 17-20C "shady" temp, to 35C in direct sunlight to 8C in proper shade. Sea temp at Lowestoft could be <10C today. So I can imagine the back of your fridge with it switched off could be < 10C too. If you don't have your fridge turned down "too cold" you are only asking it to cool 3C maybe - which means I think presents more of a challenge to the physics than dropping 15C!

Added to that those dial type controls must work relative to something and I wonder if they work relative to the "10C" rather than a proper fixed control.

You need some real numbers to work with..! Fridge temp average - when kicks compressor in, when compressor switches off. Air temp in condensor airspace etc.

Probably also worth having volts and amps drawn too.
 
ShinyShoe said:
I don't know why - but this thread makes mention of it...

http://forums.outandaboutlive.co.uk...of-Waeco-CR80-fridge-freezer-electric-/30501/

For your model.

I'm not sure I understand the physics but the compressor seems to struggle to recompress the gas into liquid when it is colder.

I've been doing some work on WiFi thermometers over the last few days testing battery strength, WiFi Strength and such like. I can go from 17-20C "shady" temp, to 35C in direct sunlight to 8C in proper shade. Sea temp at Lowestoft could be <10C today. So I can imagine the back of your fridge with it switched off could be < 10C too. If you don't have your fridge turned down "too cold" you are only asking it to cool 3C maybe - which means I think presents more of a challenge to the physics than dropping 15C!

Added to that those dial type controls must work relative to something and I wonder if they work relative to the "10C" rather than a proper fixed control.

You need some real numbers to work with..! Fridge temp average - when kicks compressor in, when compressor switches off. Air temp in condensor airspace etc.

Probably also worth having volts and amps drawn too.
Click to expand...

Yes I wonder what the dial is relative to? If say 1=8 degrees, 2=7 degrees etc then I'm not asking it to do very much by setting it to position 2!
 
NormanB said:
Sounds like it's tripping on low compression suction pressure - low gas.
Click to expand...

If you mean "Low Suction Pressure", it will not be the problem. These fridges don't monitor such things.

It could be short of gas, but until the OP reveals how he knows the fridge is reaching temp, then it's impossible to give any sort of realistic diagnosis.

In post #1 he says "It doesn't recognise that it's got to its target temperature". If it has reached target temp then it's the thermostat at fault. If it hasn't actually reached target temp then it's a whole different scenario.
 
Ambient makes a real difference as basic fridges cannot control the condensing side of the system unlike commercial and heavier systems.
The refrigeration cycle requires a minimum pressure differential to operate efficiently, that's why many domestic freezers are not recommended for use out side or in cold garages.
 
If the condenser is too cold then the condensing pressure reduces. With a simple capillary tube controlling the refrigerant flow this requires a reasonable differential pressure (compressor discharge -v- compressor suction) to achieve sufficient flow through the capillary tube, but I would expect it would be fine down to an ambient temperature around the condenser of say 10 - 15oC, and in a partially sealed space the condenser heat will raise the local temperature anyway, unless you are really blasting very cold air in.

For it to be low gas then eventually it simply would not work. Older units can leak incredibly slowly, but a detectable leak would see the unit not working at all certainly within months and likely within weeks. There won't be a pressure trip high or low on a simple Waeco. Also if the unit is old it could simply be that the compressor, likely a Matsushita Swing compressor, which is a simple Solenoid style piston with valve in the solenoid armature, is worn out.

So as requested already can you help with what temperature you are achieving when the compressor stops, and how old is the unit. If the compressor is worn out then charging more gas won't help. If it is later than 1995 it will very likely not be R12, so will be already on the current gas for these units, R134a.

A simple question also - is the ice box clear of ice ? If it looks like a mini ice cave then this would also explain your problem. Surprisingly Ice is a very good heat insulator, so a heavy build up of frost can prevent the fridge itself achieving the desired temperature inside the fridge cooled space, so the compressor runs for ever. This can also happen if the stat sensor is coated with ice.

R12 within an old fridge is less environmentally unfriendly than changing it to use R134a, as changing the gas will see the majority of the R12 go to the atmosphere anyway, and R134a is now itself being banned. It is perfectly legal to use an old R12 fridge (pre 1995), but such a fridge will be getting very tired now.

Without being able to measure system pressures then the compressor discharge and inlet temperatures will give a good idea of proper function.

If the discharge is too hot to hold then the discharge pressure will likely be OK. If the suction pipe is cold enough to form dew if you breath on it then this is likely OK. If the discharge can be held then this suggest lack of discharge pressure, and a tepid suction pipe suggests the suction pressure could be too low, both suggesting low on charge. Low discharge with cool suction suggests a too cold condenser.

Accurate diagnosis of a fridge problem is not simple without being able to see it up close and personal.
 
Thank you for that, I see the problem and how counter-intuitive it is. The fridge is only 5 years old and in summer works a treat. The back is kept clean and clear of dust and the icebox is clear of ice. Would removing the icebox door help? I'm assuming the thermostat is in the main body of the fridge? We don't need ice at this time of year but we need to keep fresh stuff fresh. Meanwhile I'll start a temperature log over the next day or so. I've also been reading the links posted earlier and this is a common problem in Australia where the distributor offers a mod for winter camper van users but I didn't understand the science of what the modification does. I'll post the temperature log in a couple of days.
 
The mod is likely to be some form of control of the condenser, maybe even adding some heat, or reducing its surface area. Similar solution to putting cover over radiator in cold climates on cars and lorry's to raise engine temp
 
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