Running a 3-way fridge

[Sooz52]

Hi, can I have basic run down of how to run a fridge for a full timer with good solar panels and propane please?
I was thinking 12v all the time, step to gas if I’m low on battery juice, and the odd 220v got rare plug ins. But I think the previous owner of my a Hymer said that 12v won’t run when driving. Is that right? Also someone mentioned that gas isn’t great at keeping low temps, instead the cooling relates to degrees below the surroundings, so in high summer my stuff wouldn’t be cold. Is that right?
Do I just leave it on auto and not worry?

 

[Max Enger]

Whilst on this subject, can someone tell me what to do with, and when to do......on my three way electolux there is an ‘Electronic Ignition ‘ button....on or off.
The fridge always fires up immediately on gas without it, so what is it’s purpose?
once, having left it on by mistake, I heard a clicking sound outside. Stopped when I realized and switch off.
Nothing in the manual.

 

[Nigel-ph]

Just to go slightly off topic, I absolutely hate the dometic 3 way fridge in my Swift. The gubbins at the back reduces the fridge volume for a start, the touch control panel keeps getting inadvertently touched and it has a habit of raising a gas fault on the control panel if it goes to gas (inadvertently) when the gas is off. Also, I believe there is an annoying 15 minute delay that means you can’t switch to gas after pulling up.... something to do with refuelling at a petrol station, and a similar delay in restarting if the gas supply is interrupted (to allow the pilot light to cool). It’s such an over complicated solution I just don’t bother with the gas function.

As others have said, 12v is only an option with the engine running and the fundamental problem is that the absorption technology is really inefficient on 12v where it would drain a battery very quickly. My previous van conversion had a 12v compressor fridge running off the leisure battery and it was much bigger inside for a similar sized cabinet with a removable freezer compartment and it was really efficient. Solar panels would easily keep it running. Of course it would eventually drain the battery after a day or so, but with electric hookup and solar keeping the battery topped up not a problem. Sod the gas, I have no intention of wild camping where it might be useful and if I could find a compressor fridge to fit the hole the 3 way fridge is in I’d change it in a heartbeat.

 

[Deep Owl]

Just to go slightly off topic, I absolutely hate the dometic 3 way fridge in my Swift. The gubbins at the back reduces the fridge volume for a start, the touch control panel keeps getting inadvertently touched and it has a habit of raising a gas fault on the control panel if it goes to gas (inadvertently) when the gas is off. Also, I believe there is an annoying 15 minute delay that means you can’t switch to gas after pulling up.... something to do with refuelling at a petrol station, and a similar delay in restarting if the gas supply is interrupted (to allow the pilot light to cool). It’s such an over complicated solution I just don’t bother with the gas function.

As others have said, 12v is only an option with the engine running and the fundamental problem is that the absorption technology is really inefficient on 12v where it would drain a battery very quickly. My previous van conversion had a 12v compressor fridge running off the leisure battery and it was much bigger inside for a similar sized cabinet with a removable freezer compartment and it was really efficient. Solar panels would easily keep it running. Of course it would eventually drain the battery after a day or so, but with electric hookup and solar keeping the battery topped up not a problem. Sod the gas, I have no intention of wild camping where it might be useful and if I could find a compressor fridge to fit the hole the 3 way fridge is in I’d change it in a heartbeat.

I have not noticed a 15 minute delay before the gas comes on. You could try turning a gas hob on to flush gas into the system, and the fridge will light within a minute if you press the “gas”button on the fridge.

My problem was seeing the dial on my Gaslow bottle showing empty in the middle of France with one of those drive-along regulators in place. I pulled into a quite busy town petrol station, and set up the system ; it didn’t fill, so the man came out 4 times to reset the dial, furiously in the end! I crept away and at the next campsite, the dial showed full! Obviously the regulator had jammed, so when we came home I changed it for a Clesse, and have never had a problem since. Incidentally, we don’t drive with the gas on, ever.

 

[Richard n Ann]

if I could find a compressor fridge to fit the hole the 3 way fridge is in I’d change it in a heartbeat.

You don't have to change the whole fridge... Maybe ?. Remove the absorption gubbins off the back (it does separate because we had a new unit) and fit a compressor kit, there's a couple of different ones depending what shape evaporator you need...

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[Nigel-ph]

I have not noticed a 15 minute delay before the gas comes on. You could try turning a gas hob on to flush gas into the system, and the fridge will light within a minute if you press the “gas”button on the fridge.

The 15 minute delay is a Truma ‘thing’. I’ve had 2 really annoying interruptions. One when there was a power cut and it wouldn't turn the electrics back on and another when I started and moved the MH a nudge with the electric hookup live and it shut the gas off (why?). At the time I was unaware of the obscure error reset procedure and kept falling foul of delay after delay. I now know to turn a knob until I see an error triangle before pressing the knob, or something like that. If you just press the knob it makes you wait 15 minutes rather than clearing the error, presumably to punish you for being stupid.....so intuitive!

I’ve since looked at some of the Dometic compressor fridges. They state power consumption is around 0.5 kWh in 24 hours with 32 degree ambient temperature. 500 watts drawn from a leisure battery in 24 hours is around 20 watts an hour, maybe an average 2amp drain given the compressor is cycling on/off and the Truma control won’t know a thing about it. I shall renew my hunt for a suitable compressor replacement or for a company that can sort it!

 

[peterc10]

The 15 minute delay has nothing to do with Truma. It is a delay on switching the Dometic fridge from 12v working to gas working when you are in the Automatic mode. That is to prevent the fridge sparking when you switch the engine off when filling with fuel (or LPG if you have refillables). If you don't want it then use the manual mode. Switch to 12v for driving and when you stop switch to gas manually and the gas will come on as soon as you do. And if you have got your bottles closed it will warn you that it has no gas, so you can go and open them.

 

[autorouter]

I’ve since looked at some of the Dometic compressor fridges. They state power consumption is around 0.5 kWh in 24 hours with 32 degree ambient temperature.

500 watt-hours is 500/12 = 41 amp-hours for a 12V battery. A 100 watt solar panel will struggle to produce that charge, even in the height of summer. But 200 watts of panel will be quite adequate.

If you want to run a fridge without gas then a compressor fridge is the way to go. There's even a case for a mains fridge paired with a small inverter, rather than a 12V powered fridge.

 

[Nigel-ph]

You don't have to change the whole fridge... Maybe ?. Remove the absorption gubbins off the back (it does separate because we had a new unit) and fit a compressor kit, there's a couple of different ones depending what shape evaporator you need...

View attachment 365235

Didn’t know that was an option, although it won’t increase the capacity, which is pathetic, it will cost nearly as much as a fridge and the awful 3 way touch sensitive controls would need to be replaced or doctored. Seems like too much bother but thanks for the info.

 

[Nigel-ph]

500 watt-hours is 500/12 = 41 amp-hours for a 12V battery. A 100 watt solar panel will struggle to produce that charge, even in the height of summer. But 200 watts of panel will be quite adequate.

If you want to run a fridge without gas then a compressor fridge is the way to go. There's even a case for a mains fridge paired with a small inverter, rather than a 12V powered fridge.

Don’t follow the maths although it’s 500 watts over 24 hours, 20 watts per hour, roughly an average 2 amp drain over 24 hours = 48 amp hours a day.

The 15 minute delay has nothing to do with Truma. It is a delay on switching the Dometic fridge from 12v working to gas working when you are in the Automatic mode. That is to prevent the fridge sparking when you switch the engine off when filling with fuel (or LPG if you have refillables). If you don't want it then use the manual mode. Switch to 12v for driving and when you stop switch to gas manually and the gas will come on as soon as you do. And if you have got your bottles closed it will warn you that it has no gas, so you can go and open them.

Ok, maybe I went a bit off topic and the fridge is manageable (but such a faff) but there is an issue to do with Truma whereby a fault that causes the Truma unit to raise an error will enforce a 15 minute delay if you don’t acknowledge the error correctly. I fell foul of it on 2 occasions before discovering the correct way. Overall I consider the 3 way fridge solution to be over complicated (try explaining it to my other half!) especially my horrid Dometic with the touch sensitive controls that keep getting touched. It’s unnecessary for how I use my MH, I have nothing but positive experience with a compressor fridge and as for the Truma control itself....

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[autorouter]

Don’t follow the maths although it’s 500 watts over 24 hours, 20 watts per hour, roughly an average 2 amp drain over 24 hours = 48 amp hours a day.

.5kWh is 500 watt-hours. 500 watt-hours over 24 hours is 500/24 = 20.8 watt-hours per hour, ie 20.8 watts. At 12 volts that is 20.8/12 = 1.7 amps. Over 24 hours that's 1.7 x 24 = 40.8 amp-hours.

That's the same end result as 500 watt-hours directly converted to amp-hours at 12V by dividing by 12. 500/12 = 41 amp-hours at 12 volts.

 

[Nigel-ph]

.5kWh is 500 watt-hours. 500 watt-hours over 24 hours is 500/24 = 20.8 watt-hours per hour, ie 20.8 watts. At 12 volts that is 20.8/12 = 1.7 amps. Over 24 hours that's 1.7 x 24 = 40.8 amp-hours.

That's the same end result as 500 watt-hours directly converted to amp-hours at 12V by dividing by 12. 500/12 = 41 amp-hours at 12 volts.

We agree, I just approximated. The other factor is that the .5kwh is a worst case at 32 degrees. Dometic quote only .25kwh at 25 degrees (approximating again) which is very efficient. I must rob a bank then get one (+£700).

 

[Pete5996]

I got fed up with my Dometic 3-way, one problem after another, and I replaced it with a Vitrifrigo 12v compressor fridge from Penguinfrigo.co.uk. Very pleased now - it just works with no hassle whatsoever....

 

[Nigel-ph]

I got fed up with my Dometic 3-way, one problem after another, and I replaced it with a Vitrifrigo 12v compressor fridge from Penguinfrigo.co.uk. Very pleased now - it just works with no hassle whatsoever....

That’s very useful info, thank you. I’m not a fan of Dometic after wrestling with the awful one in my Swift and a recommendation for another manufacturer saves a lot of research. I will take a look at the website.

 

[peterc10]

Don’t follow the maths although it’s 500 watts over 24 hours, 20 watts per hour, roughly an average 2 amp drain over 24 hours = 48 amp hours a day.

Ok, maybe I went a bit off topic and the fridge is manageable (but such a faff) but there is an issue to do with Truma whereby a fault that causes the Truma unit to raise an error will enforce a 15 minute delay if you don’t acknowledge the error correctly. I fell foul of it on 2 occasions before discovering the correct way. Overall I consider the 3 way fridge solution to be over complicated (try explaining it to my other half!) especially my horrid Dometic with the touch sensitive controls that keep getting touched. It’s unnecessary for how I use my MH, I have nothing but positive experience with a compressor fridge and as for the Truma control itself....

Sorry but I do not understand your reference to the Truma forcing a 15 minute delay. A delay in what?

Also I am not sure what Truma unit you are referring to. Is it your Truma heating unit? Or is it your Truma gas regulator (if you have one from Truma)? But in reality neither of them is anything to do with the 15 minute delay on the Domestic fridge changing from 12v to gas when it is in automatic mode and you switch the engine off.

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[Nigel-ph]

Sorry but I do not understand your reference to the Truma forcing a 15 minute delay. A delay in what?

Also I am not sure what Truma unit you are referring to. Is it your Truma heating unit? Or is it your Truma gas regulator (if you have one from Truma)? But in reality neither of them is anything to do with the 15 minute delay on the Domestic fridge changing from 12v to gas when it is in automatic mode and you switch the engine off.

You are right, what i’m going on about is nothing to do with the fridge and I have gone off topic. I have a Swift MH with a Truma wall mounted display/control unit that allows me to control the Truma heating and hot water system. With it I can select the power source for heating as gas, electric1, electric2 or a combination of both. I can also set the cabin temperature, hot water to one of 2 temperatures and blown air fan speed. It is linked to another unit (sergeant or something like that) that allows me to turn power and lights on/off and empty the water tanks together with some tellback level functions. I believe there is also some sort of link to the drive along gas regulator as it has thrown up an error for gas.

When a fault is detected an error code is displayed by the Truma controller with a message on the other unit. Once the error is corrected (e.g. power restored after a cut, gas supply restored) affected things won’t work until you acknowledge the error on the Truma unit. To do this you must turn it’s control knob until a warning triangle is displayed then press the knob. I didn’t know this initially and simply pressed the knob to acknowledge the error, which seemed logical. Doing this causes the Truma to enforce a 15 minute delay before you can try again. If you just keep doing the same thing it will never work unless you kill all the electrics to reset things. I had a very cold hour swearing at the over complexity of things until someone on SwiftTalk told me what to do. This delay is nothing to do with the fridge as you say but it is definitely a Truma ‘anomaly’ for which I can see no purpose unless, like the fridge, it is to protect the gas heater.

 

[tonyidle]

I just leave mine switched to AES permanently. It simply works.

 

[Nigel-ph]

I just leave mine switched to AES permanently. It simply works.

It would make the fridge easier to live with if I could do that. It has an automatic setting for power source that works just fine, but my partner and I keep inadvertently changing the setting due to the stupid design of the protruding touch sensitive control panel. Stand at the sink and you eventually change the fridge settings, no matter how aware of the problem you try to be. It’s this appalling design feature that sets me against the fridge rather than how the fridge works. When I contacted Dometic for a solution they basically said tough, it’s not the fridge it’s where Swift have put it and I tend to agree with them!

 

[peterc10]

You are right, what i’m going on about is nothing to do with the fridge and I have gone off topic. I have a Swift MH with a Truma wall mounted display/control unit that allows me to control the Truma heating and hot water system. With it I can select the power source for heating as gas, electric1, electric2 or a combination of both. I can also set the cabin temperature, hot water to one of 2 temperatures and blown air fan speed. It is linked to another unit (sergeant or something like that) that allows me to turn power and lights on/off and empty the water tanks together with some tellback level functions. I believe there is also some sort of link to the drive along gas regulator as it has thrown up an error for gas.

When a fault is detected an error code is displayed by the Truma controller with a message on the other unit. Once the error is corrected (e.g. power restored after a cut, gas supply restored) affected things won’t work until you acknowledge the error on the Truma unit. To do this you must turn it’s control knob until a warning triangle is displayed then press the knob. I didn’t know this initially and simply pressed the knob to acknowledge the error, which seemed logical. Doing this causes the Truma to enforce a 15 minute delay before you can try again. If you just keep doing the same thing it will never work unless you kill all the electrics to reset things. I had a very cold hour swearing at the over complexity of things until someone on SwiftTalk told me what to do. This delay is nothing to do with the fridge as you say but it is definitely a Truma ‘anomaly’ for which I can see no purpose unless, like the fridge, it is to protect the gas heater.

The heater and regulator are not linked. I am not sure about your reference to a drive along regulator. In order to use gas whilst driving you need two safety features. The first is a secumotion regulator which will turn off the gas if it senses an accident, works in a similar way to a seat belt locking up. The second is anti rupture valves on the bottle end of your pigtails which senses if your pigtail ruptures and turns off the gss at the bottle.

Both of these need resetting by holding in the button on each if you switch off the gas and then switch it back on.

It would make the fridge easier to live with if I could do that. It has an automatic setting for power source that works just fine, but my partner and I keep inadvertently changing the setting due to the stupid design of the protruding touch sensitive control panel. Stand at the sink and you eventually change the fridge settings, no matter how aware of the problem you try to be. It’s this appalling design feature that sets me against the fridge rather than how the fridge works. When I contacted Dometic for a solution they basically said tough, it’s not the fridge it’s where Swift have put it and I tend to agree with them!

Now I understand. Never heard of that problem before so I think that Dometic is right (for once) that it's Swift poor design. We have a Tectower with the seperate freezer above the fridge and the controls are between and behind the two doors. We have to open the fridge door to get to them and even then it is difficult because the freezer door is still partly in the way. As I said before we just leave them on Automatic.

 

[Sooz52]

Wire a couple of 14cm quiet computer fans on a bracket inside the top fridge vent, on a switch, which will carry away excess heat in hot weather to make your fridge work better. Our AES fridge (2013) only maintains the temperature it was before driving off. As someone said, EHU on site (you’ve paid for it) or gas on an aire/ supermarket; then remember to check for “battery” as you drive off.

I have just discovered the reason for a mystery button to the left of the fridge - it’s a fan!!

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[Sooz52]

I am almost on the road now and checking stuff out, parked on my friend’s drive for a few days.
The fridge works on gas fabulously, lovely and cold. I’ve found the button for the fan. It works on mains power too, I’m hooked up now.

However the light doesn’t come on when I try selecting 12v for driving. I’ve filled up with fuel once so just switched the fridge to 12v (so probably off) and back again. If I only really need it for refuelling then not to worry as it’s only a few minutes, but if I really should switch to 12v for driving then it’s an issue.
Any ideas? Could it be a fuse, a setting on the panel or even a bulb?

 

[DBK]

I am almost on the road now and checking stuff out, parked on my friend’s drive for a few days.
The fridge works on gas fabulously, lovely and cold. I’ve found the button for the fan. It works on mains power too, I’m hooked up now.

However the light doesn’t come on when I try selecting 12v for driving. I’ve filled up with fuel once so just switched the fridge to 12v (so probably off) and back again. If I only really need it for refuelling then not to worry as it’s only a few minutes, but if I really should switch to 12v for driving then it’s an issue.
Any ideas? Could it be a fuse, a setting on the panel or even a bulb?

It could be an internal fault (wiring or controller), fuse, a relay or the element. I think you need to get it checked because if it's the relay something else might not be working, such as charging the leisure batteries when you are driving if the charging system uses the same relay.

To check if it is working you could empty the fridge and leave it turned off for a hour or so with the door open. Then go for a drive and see if it starts to get cold. A fridge thermometer with the probe in the freezer compartment might show a fall in temperature after only a short period, fifteen minutes or so. If it is working the fine, if it isn't then it's fault finding time.

 

[Landy Andy]

However the light doesn’t come on when I try selecting 12v for driving. I’ve filled up with fuel once so just switched the fridge to 12v (so probably off) and back again. If I only really need it for refuelling then not to worry as it’s only a few minutes, but if I really should switch to 12v for driving then it’s an issue.
Any ideas? Could it be a fuse, a setting on the panel or even a bulb?

Are you checking for the light being on WHILST the engine is running?

The system needs to sense the engine running before it switches across to 12v.

 

[Sooz52]

Are you checking for the light being on WHILST the engine is running?

The system needs to sense the engine running before it switches across to 12v.

Oh, no I had no idea!!! I’ll try it out next.

 

[Sooz52]

It runs in 12v with the engine on!!! Yay. I need a manual in English. It came with a French one and a rough print of a spanish one. I’ll have a go at the spanish one this weekend with the spanish boyfriend, maybe that’ll help to understand this sort of thing.

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[Landy Andy]

It runs in 12v with the engine on!!! Yay. I need a manual in English. It came with a French one and a rough print of a spanish one. I’ll have a go at the spanish one this weekend with the spanish boyfriend, maybe that’ll help to understand this sort of thing.

Great news. Sounds like you now understand your fridge ????