Radiators only heating up while boiler fills tank

[csreades]

The house I am living has a boiler (Potterton Gold H), controller (Lifestyle Model LP112), and a thermostat (Honeywell).

Using the controller I turn on both the CH and HW, I find that the radiators only heat up while the boiler is on and filling the HW tank, after the boiler turns off the radiator starts cooling down.

I have set the thermostat to 35degC and left the CH on 24/7 but the radiators only ever heat up twice, once in the morning with the boiler and then in the afternoon when it turns back on.

If the HW tank is full then cycling either the HW or the CH does nothing.

Is there anything I can check to diagnose this problem?

 

[muggles]

Sounds like a 3-port mid position valve issue to me

 

[csreades]

So I checked, although it is really far in the back I know the make is Drayton MA1, anyway I can confirm it is the issue?

 

[Echo the husky]

Read through this it might help.