Power source for Dometic fridge, ref safe refuelling

[DavidG58]

following on from the petrol station fire thread, it got me intrigued as to ways to avoid the risk of gas ignition while stopped on a forecourt

Ours has the standard 15 minute delay after stopping, where it displays 12V operation, but if in AES it will then auto ignite the gas, even if the gas is turned off it will still fire the ignition I am sure more than capable of starting a fire if excess flammable gas is present

Options appear to be

1. Ignore the risk
2. Always set manually to 12V when driving
3. Switch to standby (off) before exiting to refuel
4. Switch to 12V before exiting to refuel

We have crash protection fittings BTW

I have discovered a potentially disastrous option if 2 or 4 is used

I travelled to Alde today for service tomorrow

On arrival I manually swapped the power source to 12V as if I was at a garage, then spoiled my own test by plugging in to hook up

So unplugged and did same again, I can firstly confirm that set that way mine does not attempt to revert back to gas after 15 minutes

However what I did spot was that it was taking power from the leisure battery not the cab battery

At a rate of 14A, I left it set this way for half an hour without any alarms but with rapidly falling battery level

Hence my concern, firstly I didn’t expect it to draw from the hab batteries at all, but if you forgot to swap back then arrived later off grid it is likely that before it went dark you would have no power left

I want to find a safe way to continue to refuel safely and think the standby option is the safest

I have on at least one occasion heard the gas cut in as I got back from paying, I think after LPG and diesel, filling and paying time can easily pass the 15 minute margin

Half an hour later, at least I know my batteries are half decent

 

[Pausim]

Shut fridge off when on forecourt. Switch back on when leaving. Don't think I have standby on my fridge. Am I missing the point?

 

[funflair]

I doubt if there are many places that you can fill with diesel and then gas without moving the van, just starting and moving will restart the 15 minutes, and yes ours runs off the tab batteries as well.

Martin

 

[DavidG58]

I doubt if there are many places that you can fill with diesel and then gas without moving the van, just starting and moving will restart the 15 minutes, and yes ours runs off the tab batteries as well.

Martin

We regularly do just that, our fillers are side by side, luckily opposite side to the fridge

 

[Pausim]

We regularly do just that, our fillers are side by side, luckily opposite side to the fridge

If you can line your toad up as well you can fill it with petrol at the same time. There must be a prize for all 3 fuels without moving but so far I have only managed diesel and petrol in one hit.

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[Reallyretired]

I never fill with diesel and lpg at the same time. It avoids confusing the check out. My fillers are on opposite sides anyway

 

[Robert Clark]

As Autogas (propane and butane) is heavier than air, I’m wondering how it could be ignited by the fridge flame?

Or is it petrol fumes which are being ignited?

 

[Pausim]

As Autogas (propane and butane) is heavier than air, I’m wondering how it could be ignited by the fridge flame?

Or is it petrol fumes which are being ignited?

Petrol fumes are also heavier than air.

 

[Wendo55]

I've never thought of turning the fridge off while filling the LPG but certainly will in future.
I have to manually turn it to 12v and must admit to sometimes forgetting and if it's set to auto it will go straight to gas when unplugged from ehu, then I'm driving on gas. Must put "FRIDGE" on a "post it" on the steering wheel.

 

[funflair]

I've never thought of turning the fridge off while filling the LPG but certainly will in future.
I have to manually turn it to 12v and must admit to sometimes forgetting and if it's set to auto it will go straight to gas when unplugged from ehu, then I'm driving on gas. Must put "FRIDGE" on a "post it" on the steering wheel.

If set to "auto" it will go straight to gas from EHU but it should then go to 12v when you are driving and then when you turn off the engine it should wait 15 minutes before going to gas, I say "should" so might be worth a check

Martin

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[DavidG58]

As I am sat at Alde with our heating being serviced that has also reminded me that moved to gas when not on hook up, something else I don’t turn off

 

[jockaneezer]

My Dometic fridge has the auto option but I've never even considered using it. I'm not sure why I don't use it, do I secretly not trust it, or am I not wanting a machine to make choices for me ? I think it's because it really doesn't need an auto setting and it's just another added complication to eventually go wrong or maybe it's a curse that's been inflicted on us by caravan users ? Before we set off, I have the fridge running off the hook up, when it's time to leave, I go in through the hab door and switch the fridge to 12 volts and once we're at our destination, the choice is either coffee or beer, both of which require a visit to the fridge where you can select your power source of choice, simples.

 

[Debs]

My Dometic fridge has the auto option but I've never even considered using it. I'm not sure why I don't use it, do I secretly not trust it, or am I not wanting a machine to make choices for me ? I think it's because it really doesn't need an auto setting and it's just another added complication to eventually go wrong or maybe it's a curse that's been inflicted on us by caravan users ? Before we set off, I have the fridge running off the hook up, when it's time to leave, I go in through the hab door and switch the fridge to 12 volts and once we're at our destination, the choice is either coffee or beer, both of which require a visit to the fridge where you can select your power source of choice, simples.

exactly my thoughts/actions only in my case it's wine

 

[andy63]

only in my case it's wine

You like your red chilled...

 

[Debs]

You like your red chilled...

Sometimes, if it's hot out

Cant see that happening for a while yet though

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[autorouter]

Hence my concern, firstly I didn’t expect it to draw from the hab batteries at all, but if you forgot to swap back then arrived later off grid it is likely that before it went dark you would have no power left

I don't quite follow what you mean. However if the fridge is set to 12V, the Electroblock will switch to cab battery (ie alternator) when the engine is running, and back to the hab battery when the engine stops.

 

[TerryL]

I discovered, after fitting a new heater element in the fridge and testing it all out, that my fridge goes straight to gas once the engine is switched off, no delay. And I bet I'm not a minority given the variety in age of vans currently on the road.

Now, despite all the advice to the contrary, I hardly ever switch the gas bottles off but in any case there is always enough residual gas in the pipes to run the fridge for a few minutes and the igniter would still work anyway. So potentially I have a bomb just waiting for the right conditions to go off!

But my gas filler is on the opposite side to the fridge, so unless I make a huge cockup of it I would consider a very small risk - well from my fridge firing up. The diesel filler is at the other end of the van so ditto. Thus any risk will come from petrol fumes from adjacent vehicles.

So why, then, are we not seeing daily instances of explosions at filling stations world-wide? I've actually refuelled the van 297 times (I keep records, sad isn't it?) over the last 10 years and nothing has ever gone bang near me.

 

[DavidG58]

I don't quite follow what you mean. However if the fridge is set to 12V, the Electroblock will switch to cab battery (ie alternator) when the engine is running, and back to the hab battery when the engine stops.

I was also confused and surprised that Hymer allow the fridge to be switched manually to 12V and draws from hab batteries when ignition off

 

[funflair]

It called choice David, I use it sometimes in Spain when we have a very low number of included watts/24hr so I will run run the fridge from 12v all morning.

Martin

 

[Lenny HB]

I was also confused and surprised that Hymer allow the fridge to be switched manually to 12V and draws from hab batteries when ignition off

Our first Hymer (2008) if no mains, gas, or engine running it would switch to hab batteries when set on AES (my mate found out the hard way). Easy fix pull the fuse marked AES on the EBL then it works as expected.
Current Hymer (2017) will only run from hab batteries for 15-20 min in the same situation but will run off the hab batteies continuously if you select 12 v manually, which is good as it gives the user the choice.

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