gas cylinder problems

[john7]

We use 6k Calor propane cylinders in our caravan with an automatic switch over for longer trips. For some time on short trips I have swapped one 6k cylinder for a 3.9k backup to cut weight. Until this weekend when the 6k ran out we have never had a switch over to the small cylinder.
When it did switch we had problems, the heater and cooker worked but the fridge was very difficult to light (we usually find it a pain but this time it took repeated tries to light it). The main problem, and why the fridge needed relighting was the water heater.
The red light came on very shortly after turning it on. Retying after 5 or 10minutes was no better. I removed the small cylinder and let some gas out refitting in the 6K position (why the fridge was out). Now it would light up for longer, up 15minutes then the red light again.
Convinced the 3.9 cylinder had “caused “the problems we located a Calor Gar dealer and got a new 6K cylinder. This time on the second start the water heater remained on as did the fridge.
The 3.9 K cylinder is a number of years old and the plastic screw bung has been kept in place until used. Now I don’t know what to do with the 3.9K cylinder, will Calor Gas take it back and if so is it a common problem that “old” gas cylinders can be unreliable and if so I am a bit concerned with changing it for a new 3.9 cylinder that may be as unreliable when needed in the future.

 

[Ancientcaravanner]

Sounds like the gas has leaked away over the years which is unusual. I have had cylinders 4 or 5 years with no problems

 

[ProfJohnL]

Hello John,

The way you have described the difficulty you are having, it certainly suggests there may be a problem with the 3.9Kg cylinder you currently have, and as ancient caravanner suggests, it may be empty or there might be a fault with valve gear but exactly what is certainly a bit of a mystery as you say you can release gas from it, and it did provide gas to a few minutes to run the items you mention.

My first suggestion is that you do exchange the 3.9Kg bottle, and try it, technically it should work. If it does, all well and good, but if it still refusing to work, then the only safe thing to do is the arrange to have the entire gas system checked by an LPG fitter.
Gas fitting, servicing or repairs are not for the armature DIYer, for your safety always use a competent person.