What is wrong with my system

[Dragonfly]

Are they Honeywell or clones (thermostat’)?

Center Thermostats.

 

[Deleted member 120897]

Center Thermostats.

So, essentially a Honeywell clone. The following links may be helpful:

Link 1
Link 2
Link 3

I think I’ve done them right

 

[Chuck]

The issue now seems like the temp on stat is reached but flame does not go off on the stat and therfore the boiler wants to fire up every few minutes but I I increase the temp to say 20 from 18c then the boiler remains fired up until the stat shows it has reached 20c and again the flame remains on display at that temp level

This is a description of what happens with a thermostat that has TPI control. Once the room is up to temperature the thermostat keeps it there by calling for heat with a boiler on/off ratio that matches the time-averaged boiler output to the losses. The flame symbol on the thermostat display won't go out until the room temperature is a degree or so above the set point (the top of the 'proportional band'), e.g. because solar gain is supplying enough heat to the room that the boiler is not needed.

 

[Dragonfly]

So, essentially a Honeywell clone. The following links may be helpful:

Link 1
Link 2
Link 3

I think I’ve done them right

That's helpful.. My issue was on link 1 and you are right it detects 1 degree difference higher or lower before flame goes off. Baxi seemed to find no fault however still replaced my hot water motorised valve as peace of mind.

I do have another issue which I will post a seperate thread on later tonight which even baxi engineer couldn't suss out so will be interesting on opinions from you pros here. Thanks everyone.