potterton puma 80 low pressure

[topcatsw6]

radiators and boiler have for last few days been "gurgling" sound like air in the sysytem. then for last few days have noticed that the pressure keeps failing and i've had to top up the water in the system. then today the low pressure light is on and despite me refilling it won't go off. pump is still working just no heating. have noticed a few droplets of water from the lower boiler casing but no leaks. have checked whole house. is it an air lock or something major? system and all pipes are only 5 years old....

any ideas have already replaced the circuit board this year which cost £300 so don't want another plumber visit.........

 

[galwag]

puma low water pressure switches are prone to blocking
drain system (dont use isolating valves on boiler or they will probably leak)
unscrew to remove lwps & unblock
refit lwps, refill & vent - job done
you will still need to sort out leak though

 

[ChrisR]

Leak most likely to be the auto air vent, top left of boiler - just replace it with a 3/8th" one bought from a plumbers merchant. Also there's a sensor screwed to internal pipe lower right which usually drips a bit.
As a strictly temporary measure, you can unplug the LPS to bring the boiler back on. It's the 2 pin connector lower left corner of ther pcb. Yellow wires iirc. Do not leave it disconnected - if the boiler runs dry it will cause damage