S plan no heating

[mamamaka]

Hi, I have no ch on an s plan system, timer and stat are both calling, I have the following on the 2port valve wiring - 240v on grey, 0v on brown and 0v on connection no 4, what do I need to replace?

 

[Johntheo5]

If the timer & stat are calling then you should have 230V on brown, this then drives the valve motor to open it, a internal switch then connects the permanent live (grey) to the orange to switch the boiler on.

 

[gas112]

0 volts at brown then Check you have 240 going to roomstat and 240 coming out of it if nothing going to it your programmer is faulty if nothing coming out then room stat faulty

 

[DP]

0 volts at brown then Check you have 240 going to roomstat and 240 coming out of it if nothing going to it your programmer is faulty if nothing coming out then room stat faulty

Not the first time got called out to no heating. The roomstat is sat at 10 or 12 degrees