Central heating problem

[greenteam]

Can anyone help, when the hot water starts on the central heating system, it is also heating all the radiators even when the are set to off. Have replaced the programmer but still the problem continues.
Would be grateful for any suggestions.

 

[masona]

Could be by-passing the motorised valve ( sticking valve or not shutting probably ) You could try and move the lever back & forward to clear it,failing that drain down system and test the motorised valve or renew.If it a combi boiler then it could be your diverter valve.

 

[greenteam]

Thanks, will try your suggestion.

 

[MANDATE]

I came across a similar problem about ten years ago in a modernised terraced house. By following the flow of both hot water and central heating water I found when central heating was off the hot water was going to the right and the left at a tee junction, the water going right was in reverse to the normal flow and this was heating the radiators.
The cure was installing a spring loaded 'one way valve' in the heating circuit (purchased from Wickes approx £5)

 

[greenteam]

Many thanks, all ideas welcome.