Jeavons / Cavagna Automatic Cut-Off Regulator
This design was made by
Jeavons, Cavagna, and some others. It is invariably either
grey or green. It is typically located at the LPG tank
or, less frequently, on the outside of the building where
the gas supply enters the house. It has two separate reset
mechanisms, (a) one for locking out due to too low a pressure,
highlighted in the left red circle, and (b) one for too
high a pressure, in the right-hand red circle. It is very
unlikely that the high-pressure lockout will have tripped.
For the low pressure lockout,
unscrew the cap (in the left-hand circle on the previous
picture) revealing the plunger shown on the left. Gently
pull the plunger out, you should hear the gas going through
the regulator as it fills up the pipework with gas. When
the flow stops, let it go, and replace the cap.
For the high pressure lockout
(again it is very unlikely that this will have tripped
and it usually indicates a more serious problem), unscrew
the cap (in the right-hand circle on the picture at the
beginning of this section). Depending on the model, either
(a) the cap comes off easily to reveal a plunger similar
to the low-pressure lockout or (b) as shown on the left,
the cap unscrews but stays affixed to the plunger. In
either case, gently pull the plunger or cap out, you should
hear the gas going through the regulator as it fills up
the pipework with gas. When the flow stops, let it go,
and replace the cap.