LPG tank

We have a Malvern with an LPG tank. when we first got it, we took it to our local filling station to fill it. Apparently it has a 25l tank and will stop filling at 20l. The process seemed a bit odd, took over one minute per litre for the first 10 litres, then the filler rushed up - we stopped it when it said 22 litres as we were concerned that it should have shut off by then. We have just been away in our motorhome with no hookup. I was woken overnight by the fridge 'clicking' like it was trying to ignite the gas. I just got up and turned the fridge off as it was stupid o'clock in the morning. When we got up I went to put the kettle on - no gas - so assumed we had run out. We found an LPG dealer and filled up. This time it filled quickly but shut off at less than 14 litres. Does this mean that we did have gas and something, somehow had shut it off, or is it normal to shut off so quickly? We are now completely confused!

The shut off should work at 80 per cent of the tank capacity in order to allow for space in the tank for the LPG to change from liquid to gas.  If the tank filled any further, there would be the danger of pure liquid gasentering the pipes and potentially turning your gas hob fridge etc into a flame thrower!  Best have your system checked by a gas specialist as that could potentially be dangerous IMHO.

We have a fixed underslung gas tank and fill up at fuel stations.
I often find when pressing the fill button it can take a while before the gas starts to flow. I've even had the previous users gas quantity still showing and not resetting until the gas starts to flow then one can see the litres being used.

Filling up with gas of course still requires you to turn on (and off when not in use) any gas isolation valves you may have usually hidden in a cupboard somewhere. Even the gas tank has an isolation valve /regulator which we leave on all the time.

Check your pipe feed from /to your gas tank regulator. If it's rubber I recommend changing it to a stainless steel braided hose as the rubber ones are prone to split on bends.

We often 'camp' off grid especially when travelling abroad so regularly use all gas appliances with the added bonus of being cheaper than electric hook up.

So on arrival:
Turn on 12 volt electric system 
Turn on fridge isolation valve tap.
Set fridge to use gas and press the ignite button. Hear the clicks and watch the needle rise. Hold ignite for 10 seconds then release and check the gas flow needle/ indicator is still showing it's working ok.

Make a brew on your gas stove !!

That does sound odd Supapen. The only explanations I can think of are as follows:
Your first fill very slow then the pump went fast sounds like a faulty delivery pump. It almost sounds as if the bulk tank was running out of liquid. However, that seems unlikely - or at least very unusual, you would think that a pump would not operate if the bulk tank was empty. I am not intimately familiar with how those pumps work but I imagine they don't use electricity to actually pump, I would have thought they just rely on the very high pressure inside the tank to force the liquid out. They do of course need electricity to operate the display of the volume dispensed.
Your second event - no gas and 14 litres to fill up sounds very wierd indeed, almost as if the first fill was water. I wonder if this is a possibility: that the first bulk tank was putting water into your gas tank. Suppose the first bulk tank was nearly empty. As the LPG runs out of it, the space has to be filled with air. Condensation may form inside the bulk tank which of course would run down the inner walls. Had it run out of gas and was delivering water to your on board tank? I don't know but I would love to find the explanation.
You then refilled your tank at a different place and you don't say so but I am assuming that your gas appliances now work. Another thing I don't know is whether water floats on top of LPG or the other way round. If your appliances are now working and my theory is correct, then the gas must be floating on the water.
This is a fascinating problem and I would love to know the answer. Can you call GasIt - who supply A/S tanks I think - and ask them?
You won't have any redress from the original LPG supplier, as with water in petrol station tanks they are never responsible for anything that goes wrong.

As a generalisation to anyone else reading this thread, the following scenario could happen if you have a post-2014 I think gas installation in your motorhome, and it would cause your gas appliances to stop working. Suppose you fill with LPG, then soon afterwards you have no gas. Have you done an emergency stop, or even a not-emergency-but-rapid-stop? If so your gas regulator mechanism may have triggered its automatic shut off valve. I had this once, when I braked hard. If you have a post-2014 installation, there is a green 'button' on the regulator bunch of aluminium apparatus just downstream from the gas bottle - LPG or regular Calor gas type of bottle. To reset it you have to push the green 'button' in and hold it for five seconds while you can hear a ball bearing rattling around inside. When it stops, release the green 'button'. I have put commas round the word  'button' because it doesn't stick out from the aluminium casting of the regulator, it looks just like a green paper circle stuck to the casting. When they call it a button that has to be pressed in you imagine you should be looking for a protruding button, not one that is exactly flush with the casting, but it does indeed push further into the casting. It works by shoving a ball bearing into the outlet of the regulator, cutting off the gas supply to the vehicle. The gas pressure holds it in place, you won't get it running again by driving over bumps. When you press the green 'button' in it lifts the ball bearing off the regulator outlet and once the regulator is full of gas the ball bearing moves away from the outlet so your gas flows properly.

Do these help?

I had this slow to start filling on my last fill up at Chieveley on A34, I was holding the button in and nothing! strange I thought so tried again, then got fed up and stormed into the shop, when I got to the front of the queue, the lad said, "oh we need to press the button in here also before you can fill" Thanks on my exit I said well can you keep an eye on it then. Me must have as I filled in seconds, 9.95 ltrs.

Maybe this is what happens to others and no problem with your system.

RIP.

--------
Richard

PS. They were more interested in selling coffee!

gassygassy and Tinwheeler ….. Thanks for this, filed incase ever needed .


Niall.

You were lucky to find an LPG station since Shell and BP decommissioned their pumps.

BornAgain wrote:You were lucky to find an LPG station since Shell and BP decommissioned their pumps.

Shell have only removed pumps from Shell owned filling stations, not franchised stations. Still  over 1000 places to get lpg.

Paulmold wrote:

BornAgain wrote:You were lucky to find an LPG station since Shell and BP decommissioned their pumps.

Shell have only removed pumps from Shell owned filling stations, not franchised stations. Still  over 1000 places to get lpg.

Thanks for that info Paul, I did wonder why a local Shell station was still selling LPG when all the others had gone!

Actually I have been a silly billy. LPG bulk tanks are not vented, they don't need to be as the pressure of the gas inside would escape if they were vented.
Slap on the wrist for me for saying they are. I was thinking of the scenario where underground petrol tanks are vented to let  air in as petrol is pumped out.
Send for the men in white coats.
I think the slow delivery may well have been the cashier not pressing the go button.

And yes the first of Tinwheeler's photos shows the green button that doesn't stick out. That's the one to push and hold for 5 seconds if you brake suddenly and the gas shuts off.