On 18 Nov 2006 17:39:37 GMT, (Andrew
Gabriel) wrote:

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.

Turning down the thermostat that low, while aiding boiler efficiency
in space heating applications, is not really compatible with heating a
hot water cylinder to usable, i.e circa 60 deg C temperatures.


--