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I have Under-floor central heating with 4 zones each with own thermostat. Gas boiler & timer. 2 wall rads.(in bathrooms) which heat up whenever either CH or Water selected.
Told most efficient way to use is leave system(4 years old) ‘ON’ and regulate everything with thermostats.
I even set thermos to 10degs but boiler still appeared to chunter on at high temp and rads stayed very hot.
My question:
Why doesn’t the boiler shutdown to standby when all zone temperatures well exceed that set on the thermostats.
Regards

This is a tricky 1. I might be way off here but I think the stats controlling your 4 zones are only controlling the zones and not the boiler. The boiler is only controlled by firstly the timer being on constant then its own stat. So if all the zones are satisfied they close and the boiler continues to heat the two radiators.

If this is right then it may want wiring up differently.

[quote="gisago"]This is a tricky 1. I might be way off here but I think the stats controlling your 4 zones are only controlling the zones and not the boiler. The boiler is only controlled by firstly the timer being on constant then its own stat. So if all the zones are satisfied they close and the boiler continues to heat the two radiators.

If this is right then it may want wiring up differently.[/quote]

Thank you for your input. I got further research done and yes you are correct in saying that the zones have their own 'stats and the individual area valves(of which there are 6) also seem to shut down OK when zone stat temp is reached. Also as you obviously know I have to leave at least one rad on for the system to work properly. The further concensus of opinion was that this is the working correctly and I should control everthing by temp control. However,I can't get my head around this. Surely if the rads are heating up continuously then I am burning gas which is costing money. I don't want or need the rads on unneccessarily.
My simple logic says that the boiler should shut down to at least some sort of a standy position when zone thermostat demands are satisfied. Maybe you have it right and although I have all the boiler manual plus the CH floor diagrams showing electrics etc. I can't come up with an answer. Should I contact Ferroli who are the Boiler manufaturers?.
Regards

Hello again, it may be worth talking to Ferroli or even the installer if you can.
Personally I would make more use of the timer and maybe not leave it on constant. I wouldnt want my bathroom rads on 24/7 either. Im pretty sure you could keep the house warm even if it was timed to shut down at night. With underfloor heating it takes a long time to cool down so i doubt you would wake up to a cold house. Try timing it to come on an hour before you get up and off for a spell during the daytime if no-one is at home. I know you are concerned about efficiency but i bet if you note how much gas you consume as it is at present and compare it with what im suggesting you will be better off.
(I'll probably start an argument now suggesting that)
Hopefully this helps you out a bit.
You could get really technical and zone the 2 rads off and control those with thermostats but it depends how much you want to spend on altering the system etc. Try option 1 and see how you get on.

[quote="gisago"]Hello again, it may be worth talking to Ferroli or even the installer if you can.
Personally I would make more use of the timer and maybe not leave it on constant. I wouldnt want my bathroom rads on 24/7 either. Im pretty sure you could keep the house warm even if it was timed to shut down at night. With underfloor heating it takes a long time to cool down so i doubt you would wake up to a cold house. Try timing it to come on an hour before you get up and off for a spell during the daytime if no-one is at home. I know you are concerned about efficiency but i bet if you note how much gas you consume as it is at present and compare it with what im suggesting you will be better off.
(I'll probably start an argument now suggesting that)
Hopefully this helps you out a bit.
You could get really technical and zone the 2 rads off and control those with thermostats but it depends how much you want to spend on altering the system etc. Try option 1 and see how you get on.[/quote]

Hi again and ta for your time in replying.
I have used the Ferroli site and sent their techies an email. Awaiting reply. I could just switch the system 'on' and 'off. In fact that is what I did until recently but was advised against it as underfloor heating takes many hours to reach thermostat temps and thus it was inefficient to do it this way. Hence my change of operation. Of course in about a months time I wont need the heating side on just a timer for the water. I am lucky in one respect that I live in a south facing apartment that has a very large floor area of about 1,100 sq ft and continuous glass walling. So for example when the sun shines it is like living in a conservatory. The downside is on a non-sunny day the heat does the opposite. This is my first winter in the place so I don't have a true record of past performance.
Anyway once again many thanks for your input.