Programmer or Thermostat Fault

[smaug]

The Central Heating system is controlled by a Lifestyle LP522 Programmer and a Honeywell Room Thermostat (I believe a T6360B).

The boiler fails to react. I do not suspect a boiler fault as the boiler fires when called for (hot water) from the other half of the LP522 and from a separate programmer for the heated towel rails.

Any suggestion on how I can establish whether the Programmer or Thermostat is at fault would be appreciated.

 

[Dan Robinson]

More likely the zone/diverter valve.

 

[jackthom]

Is there one of these in the system ?

Untitled

• jackthom
• 19 Dec 2008
• 18

and do the radiators get hot when hot water and heating are on together ?

 

[smaug]

Is there one of these in the system ?

Untitled

• jackthom
• 19 Dec 2008
• 18

and do the radiators get hot when hot water and heating are on together ?

Thanks

There is a Lifestyle 2 port motorised valve.

No. The water heating is fine but the central heating doesn't respond when both are on at the Programmer or only one.

 

[jackthom]

Sorry to keep asking questions but does the pump run at all in any mode of operation ?

If you have a multimeter or mains tester screwdriver you can check that the room thermostat has permanent Live on terminal 1; and when the thermostat is calling for heat terminal 3 should also be live.

 

[smaug]

Sorry to keep asking questions but does the pump run at all in any mode of operation ?

I believe that it is running from the vibration and the fact that it is quite warm

 

[jackthom]

If the pump runs when there is a demand for central heating and stops when the room thermostat is turned down, the thermostat and programmer are probably OK.

In which case the microswitch in the motorised valve could be faulty.

 

[Dan Robinson]

Unless the OP tells us what boiler and control valve set up he has, this is all fruitless speculation.

 

[smaug]

Unless the OP tells us what boiler and control valve set up he has, this is all fruitless speculation.

I do appreciate your help though I guess that if I understood the system better I might not need it!

The Boiler is a Potterton Suprima 100 but as I said I don't think it is the problem

As I said earlier the Programmer is a Lifestyle LP522 and the Thermostat, a Honeywell ( I think T6360B). The motorised valve is a 2 port Lifestyle.

I don't know whether any of that helps but I have managed to get heat now by manually operating the motorised valve.

Does that help pin the problem down?

Thanks again.

 

[Dan Robinson]

Assuming you have two of those valves then yes.

The one you opened manually is faulty. The other one is what is bringing on the boiler and pump (the latter is wired through the former).

 

[smaug]

Assuming you have two of those valves then yes.

The one you opened manually is faulty. The other one is what is bringing on the boiler and pump (the latter is wired through the former).

Yes there are two valves. I assumed that the other one (another Lifestyle 2 port) was operating the water heating.

Sounds as though I need a new motorised vale when the Plumber gets round to ringing me back.

Thanks again