hot water locking out

[shellb]

hi ya, I have a potterton 80 combi, When running the hot tap I get hot water fine but turning off the tap the boiler stays lit until the water in the pipe becomes steam and vents and the sytem locks out, most of the time it resets after waiting 5 mins for system to cool down but today as soon as I take it off standby (heating set to off) the boiler lights up as if the tap was running ( taps off, non dripping ), With the cover off a red light on the PCB is now on all the time, Is it a sticking flow valve??,if so can this vlave be cleaned out/greased or do I need a new one? Are they easy to fit?
Central heating works ok until the hot water locks it out, Anyway to disable the valve so I can just get the heating working.

cheers
S

 

[meldrew's_mate]

If it's similar to the Puma there's a dedicated flow swich with a microswitch attached; pulling one of the wires off and insulating it should get the heating to go until a new switch can be fitted, but without DHW. Again, if it's like the Puma the switch is adjustable, so you may be able to wind out the microswitch until the led goes off at low/no DHW flow.

 

[shellb]

sounds like the middle one in the valve block, There is a blue screw with a clear plastic cover, I might try adjusting it first if it stays locked out again, seems ok today, Its worse when the heating has been on for a while.

thanks for your help

 

[Agile]

I think he is talking about the gas valve now!

Time to evacuate the neighbourhood?

 

[shellb]

no where near the gas...lol

 

[Agile]

The blue screw under a clear plastic cover is on the mod coil of the gas valve !!!

 

[shellb]

BOOM!!!!!!!!!! only joking
I did not mean the gas valve on the left..