Simple 'fault' on Combi, probably due to room stat.

[Tunni56]

I say 'fault' in inverted commas because it's probably not a fault. Boiler: Intergas 24/18 delivers DHW superbly, but not firing on Central Heating. The boiler is second hand and was removed from a property that had a large extension and was underpowered for the additional rads.

The boiler has now been installed in a small flat but the wall mounted thermostat is old and knackered so needs replacing. Therefore no room stat has been connected. I think this is why the CH doesn't fire ie the boiler doesn't know it needs to fire up. Does this sound like the most probable cause.

I notice on the electric connection strip for the thermostat that there is a 24v low voltage option or mains powered one. As I need a new stat whats best to go for?

Regards
Tunni

 

[gigz]

If its had a stat connected at the last property i woukd say it needs tge link putting back in, or as you say fit new stat (link in would prove boilers ok).
As regards best stat, wired stats are much more reliable than wireless (my opinion) but obviously wireless are more versatile.

 

[Agile]

Although few do, I would suggest a 24v stat connection would be safer as that reduces mains on house wiring.

Tony