Potterton Suprima 40 Boiler Continues Heating Radiators Even when Clock off Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[Engineersparks]

My central heating system has a Potterton Suprima 40 boiler which continues to heat radiators even when time clock is off and room thermostat is turned down. The green and amber light on the boiler appear to be working correctly so any help would be appreciated.

[Engineersparks]

When I say the radiators continue to heat I mean they get scalding hot even when the programmer is off and the room thermostat is turned way down. Could it be the motorized valve?