Glow-worm space saver mk II pilot light keeps going out.

Hi I have a Glow-worm space saver mk II boiler and the pilot light keeps going out. Typically there is no problem in relighting the pilot light.

The pilot seems to go out at the point when the boiler stops firing up. For quite a while it was fine just doing h/w and cutting out when the central heating was switched on. Now it seems to also cut out when the h/w only is on.

I have had it serviced and just had the thermocouple replaced... but to no avail. The system is gravity h/w and pumped central heating (C-plan?).

Other symptoms... which may or may not be related are:

1. The central heating pump carries on running (indefinitely... many hours) when the central heating has turned off on the timer switch. Turning the h/w timer switch off and back on switches the central heating pump off... as does turning electrical power off and on to the boiler.

2. Sometimes, when the central heating has been on... but it is now off on the timer switch, the radiators stay hot... in fact they they get scary hot.

Any help/ideas gratefully received.

Sounds like it's overheating.
Turn the boilerstat down - you've propably done that already.
Check the boilerstat sensor is properly located in its sheath following the service.

1. The central heating pump carries on running (indefinitely... many hours) when the central heating has turned off on the timer switch. Turning the h/w timer switch off and back on switches the central heating pump off... as does turning electrical power off and on to the boiler.

2. Sometimes, when the central heating has been on... but it is now off on the timer switch, the radiators stay hot... in fact they they get scary hot

Click to expand...

Sounds like ANOTHER motorised valve sticking open