Lpg gas bottles

[Daveg666]

If I try to charge my lpg gas bottles only 1 fills. I have been told about non return valves but no idea i have an autotrail cheyenne. Can anyone help

 

[Minxy]

If they are both refillables they should have a pipe going between them in addition to the ones from each to the regulator and one from the filler to one bottle.

Were both gauges showing empty? Try tapping the empty one to see if it is stuck.