Combi Heating Temp

[kenny1234]

I have just had to replace my central heating Combi boiler (which has a wireless thermostat). I find that even though I have set the room temperature at 20 degrees,the boiler seems to still be firing when the temp in the room ( where the gauge is) shows 22 or 23, rather than cut off at 20. Is this normal?

[The Builder]

Are you sure it's the "Heating" coming on?
Most likely a "Hot Water" function called "Pre-Heat". Completely independent of the Heating temperature control.

"Pre-Heat" just makes sure the Hot Water temperature is right up, ready for any demand from a tap.

[Atheist]

Regardless of what your controls say, is your room overheating? If not, then probably the boiler is making sure your hot water is ready and waiting within the boiler, radiating heat unnecessarily, just on the off-chance that you might turn a hot tap on. If you can figure it out from your instructions, you might prefer to make the hot water supply only available when you turn on a tap, rather than sitting there giving off unnecessary heat into the room. If your lifestyle suits the hot water being there all the time, then stay with it; but give it some thought.

[kenny1234]

I can see your point about it possibly being the "pre-heat"----but the radiator symbol is flashing whilst system is operating above the temp set!!---would that be the case during "pre-heat" ?

[kenny1234]

PS----I know the thermostat is sending the signal that 20 is enough, because the green receiver light goes out when 20 has been reached

[kenny1234]

Any help please regarding the flashing radiator symbol. (whether that applies to central heating only or not?)

[davebro]

have you got the instruction book?

[SparklyKid]

I had this once when I replaced the batteries in the wireless room stat.

It was on "Auto" instead off "On". On "0n" it only fires up when room drops below designated temp.

[kenny1234]

Just got round to looking inside my thermostat-----can't see any auto/on settings anywhere!