On Tue, 13 Jan 2004 23:00:11 GMT, Harry Bloomfield
wrote:


It is never more efficient to leave the heating on for a period than to
turn it off.

It can be, depending on the thermal behaviour of the house and the
control system. Systems with setback, optimum start and outside
temperature compensation can result in little or no temperature
overshoot at the wrong times and more accurate temperature control
than where a simple thermostat and timer is used.


Having said that, we do leave our heating on, but set to
retain a low temperature. Even when the house will not be occupied for
several days, we leave the heating on set at 5 deg C to protect against
frost.

If your boiler cycling on and off for 30 seconds at a time, when there
is no obvious call for room or water heating, then there would appear
to be something wrong with it.

That is typically a lack of interlock on a non-modulating boiler.


..andy

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