"Andrew Gabriel" wrote in message
...
In article ,
"Edward Holt" writes:
I've just had a condensing Worcester 24i junior installed.

If I control the room temperature using the TRVs (as advised) what should
I
set the temperature control on the boiler to be?

Most efficient boiler operation is to have the water as cool as
you can whilst it is still able to heat the house. You will need
to turn the water temperature up higher as the outdoor temperature
drops, and also if you are heating up the house from cold. Exactly
what that temperature is depends how large your radiators are. If
they were designed for a condensing boiler, it might be as low as
45C (which is what I use), but if they predate the condensing
boiler, you might need the water hotter in order for the radiators
to get enough heat transferred into the rooms. Try turning it down
until the house starts getting colder, and then turn it up a little.

I've got a digital timer on it, I've got a small radiator near the boiler
without a TRV but I've not got a room temperature control.

Sounds like the installation does not conform to Part L. There
should be something to stop the boiler firing up when there is
no demand for heat, and that's usually done with a room stat
in one room which doesn't have TRV's fitted. Does the radiator
with no TRV stay hot all the time?

--
Andrew Gabriel

Thanks for the good advice.

I'm in Scotland and this combi is a replacement for a non-condensing Ariston
unit which failed after 10 years.

The radiator without the TRV does stay warm - very warm, easily the hottest
one in the house (it's in the hall).

I was concerned that if I had the heating on the boiler set to max then the
TRV would reject the hot water and the radiator without the TRV would get
all hot water and get dangerously hot. I guess that having a room stat would
avoid this?