Roger Mills wrote:

"The Natural Philosopher" wrote in message
...

I don't know what turns *your* boiler off. In my case it turns itself
off when the temperature of the water in the return path matches its
internal thermostat settings.


Yes, but the point is that it then turns itself *on* again when the boiler
itself has cooled to below its stat setting - regardless of whether any
heating is needed in the house. This is clearly wasteful.



Er, no, it doen't. The fact that heat has been taken out of the water
indicates that the house has cooled enough for some TRV's to open...
Ok there is marginal loss through hot water pipes under floors etc that
set a base level of heating that the system never drops below, but I
would suggest that anyone who runs their heating at all when they don't
actually need their radiators on is a bit of a plonker.

In more normal situations, the slight heat loss through the pipework is
far more than compensated by not having UN TRV'ed radiators overheating
rooms that are not in use, or need to be set at lower temperatures.

TRV'ing everything and ruinning the whole sytem on a time clock is far
more energy efficient than having a master thermostat and no TRV's


Roger