No heating until I run off the hot water

[patta32]

Hi, I have a y plan heating system but am not getting any radiators heating up until I've ran off the hot water via the bath.
What could be causing this problem please?
Thanks

 

[cross thread]

may be a faulty cylinder stat not switching over when satisfied

 

[patta32]

Thanks for that.
How could i test if its working?

 

[seco services]

sounds more like the valves jammed in mid position.
so boiler only kicking in when hw/heating called for not heating only.

what valve is it ?

 

[patta32]

its a honeywell 3 port valve

 

[seco services]

turn heating off hw on only. boiler firing up to heat hw.
is the lever on the end of valve floppy or has it got resistance ?

 

[patta32]

the lever does not have any resistance when I do what you said

 

[seco services]

so you had heating off hw on only was the rads still getting hot ?

 

[patta32]

no, they dont start getting hot until i run the hotwater off. I turn the bath on and when the hot water begins to run cold, i stop the tap. The radiators then start to heat up

 

[seco services]

is that with hw on only at programmer rads get hot as well as hw ?

 

[patta32]

that is with CH on. No heat in radiators till I run the water off

 

[seco services]

that is with CH on. No heat in radiators till I run the water off

you are running the water off from the cylinder to get the cylinder stat to kick in to reheat the cylinder water.
but with the hw on only at programmer and boiler firing up to heat the cylinder again do the rads get hot aswell ?

 

[patta32]

I put CH on, on the controller. The HW switch is left off. The radiators will not heat up. I then run the hot tap on the bath. The water is hot. I continue to run this water until it goes cold. The radiators then begin to get warm shortly after.
This is the only way i can get the central heating on.

 

[seco services]

how longs it been like this ?

 

[patta32]

couple of months now. was working fine till that point