3 port valve

[madmat34]

hi guys
I've got a system thats giving hot water but no central heating.
if i push the 3 port valve lever to manuel it works for a little while then stops again.
is it my 3 port valve
thanks

 

[Softus]

I reckon I have the answer, but I'll leave you to guess at what it is while I occupy myself guessing at what your "system" comprises.

 

[madmat34]

what do you mean??

 

[madmat34]

its a potterton boiler
hot water tank
pump
controler.
if you put the heating on the pump doesn't run
if you put the hot water on the pump runs.
so is it the 3 port valve??
ta muchly