POTTERTON PROMAX NO CH BUT HAVE HW ??

[okneedhelpplease]

Hi i have a pott promax he24 plus boiler, the hw is fine but no ch it is about 5years old can anyone please advise. When i switch to ch the boiler fires up but when i switch to ch it does not fire up ?? when both on togrether it fires up till hw gets to temp ??

 

[gas4you]

I assume this is a system boiler or open vent?

In this case it will be your 3 port valve head faulty, or the ch 2 port valve head.

 

[okneedhelpplease]

i have checked both 2 way valves and they work fine

 

[gas4you]

Have you checked there is 240VAC on the orange wire when there is a demand for CH?

The valve motor may work but the microswitch in the valve head has probably broken.

 

[okneedhelpplease]

Hi dave an thanks for the reply. The orange wire woul come from which of the 2 two way valves or does it not matter

 

[gas4you]

There will be an orange wire from both valves.

You need to turn off electric to heating system, temporarily disconnect the orange wires, leave safe, turn back on, select CH only and check to see if there is 240VAC on the CH valve orange wire.

Only do this if you feel competent at testing live electrics, otherwise get a heating engineer or sparks in.

 

[okneedhelpplease]

Thanks Again Dave. I will do ths in the morning now so plase keep in touch.

Regards Andy