Central Heating coming on when it shouldn't?

[Sheraz]

My programmable thermo needed replacing last week which I replaced with the same model (Salus RT500)

However, I thought it was all sorted until I noticed that once I set the program times and temp, the central heating sometimes stays on even though it has reached the room temp.

For instance, I've set the room temp to 23C but the central heating is still on even though the room temp has reached 25C (the flame on the thermo is switched off but seems like the Boiler doesn't want to listen to it)

The other weird thing is that the boiler then switches off when the program has got to next time lapse (for instance I set the temp to 23C from 5am to 7am - the rooms heats up to this temp at around 6am but the boiler stays on and only at 7am it decides to switch off)

To complicate matters even more, once the program has switched to a low temp setting after 7am, the boiler then sporadically comes on intervals on 10 mins for about 5 mins and then switches itself off again - what the hell is this about?

I'm really confused now, is this a boiler/wiring issues or the new thermo program problem (or both)

Any ideas?

Thanks in advance

Sheraz

 

[D_Hailsham]

My programmable thermo needed replacing last week which I replaced with the same model (Salus RT500)

Why did you replace it?

 

[Sheraz]

The receiver stopped working, it was switching the boiler off but not on.

 

[D_Hailsham]

So it's the wireless version; you hadn't mentioned that.

Have you checked communication between the two parts? (Instructions on page 11 of manual)

What are your five time/temperature settings?

More details about your system would be helpful.
Boiler info?
Do you have a HW cylinder?
Any motorized valves?