On 08/03/2020 10:13, Tricky Dicky wrote:

On 08/03/2020 09:04, Tricky Dicky wrote:
The OP did not mention if the heating system had TRVs throughout. I have come across systems where all there was a programmer with no room stat and all the temperature control was through the individual TRVs in fact a friend of mine had that exact system. I have virtually the same having equipped all my radiators with Hive smart thermostats except for the bathroom which is the official system bypass and the kickspace heater in the kitchen which has its own thermostat. If the OP has a system as mentioned above the unwired room stat may just be a redundant item from a previous setup.

With 'smart' TRVs which ensure that the boiler only fires up if there's
a call for heat that would be OK but I don't think traditional 'dumb'
TRVs satisfy Building Regs requirement because the boiler will keep
cycling to maintain the heating water temperature when not required.

Mike that may well be the case now but certainly in the 80/90s when I first came across this system it was an option. I know my friend did have a cylinder stat and twin valves and do not recall him complaining of the boiler short cycling. I seem to remember he had one radiator with standard valves to act as a bypass.


I believe that it was around 2010 that Part L banned such installs.


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Adam