Central Heating Controls

[johns10]

From johns10

Hi I hope you can help.

My central heating system has two radiator circuits, upstairs and downstairs, each controlled by a room stat (Potterton PRT2). (There is also a separate hot water circuit)

The problem I have is that the downstairs PRT does not demand heat from the boiler. But when the upstairs PRT comes on heat circulates through both circuits and the downstairs PRT then regulates the downstairs temperature; until the upstairs PRT is satisfied.

When the programmer comes on the downstairs PRT shows a green demand light but the pump does not run: until the upstairs PRT comes on in demand mode.

As far as I can tell both zone valves work as directed from each PRT.

thanks

 

[45yearsagasman]

Id put money on it being the downstairs zone valve,having a faulty end switch or beginning to sieze up.