potterton suprima 60l

[reesd]

I have recently had a potterton suprima 60l installed. It works fine on hot water only, but when central heating is selected, the radiators heat for about 45 minutes until the boiler trips out (red light on boiler).

Potterton have been to check the boiler and its installation and confirm it is not the boiler but a problem with the central heating system.
Has anyone any ideas why the boiler trips out with such regularity only when the central heating is on, but is okay when heating hot water only.

 

[scatmanjohn]

What type off system do you have.

2 x moterised valves?

1 x mid position valve?

Thermostatic radiator valves on all rads?

Bypass fitted?

 

[reesd]

There is a 3 way motorised valve and thermostats on all radiators, i don't know about a 'bypass' though. The boiler is a 'system' boiler as the hot water tank has been retained and this is fitted with a thermostat.