"Mathew Newton" wrote in message
...
On 18 Oct, 21:51, "Angela" wrote:
I have a Honeywell CM67 on my central heating and I have noticed that it
is
calling for heat several times an hour even though it states that it is
at
the correct temperature. When it is at the correct temp it only calls for
heat for a minute or two. This seems a real waste.

Hi Angela,

The late Mr Hall wrote an excellent post on this some years ago which
will explain in detail what's happening and why:

http://groups.google.co.uk/group/uk....ced42?hl=en-GB

You could try cutting the cycle rate down to 3 as there may well be
benefits as far as boiler life is concerned although do keep an eye on
how accurate the temperature is then maintained.

Mathew

That was a very useful post thank you Matthew. I "think" I now understand
what is happening. This is a new house with a new boiler but I notice that
the CM67 isn't sold any more - the developers/installers must have had a job
lot to get rid of. It seems fine though. I have only just started putting
the central heating on proper and it would appear that this thermostat can
"learn" and I probably haven't given it time to do that. I'll leave it at
the defaults for now and see how things go I think.

Angela