Central Heating comes on when only Hot water is on

jrawle

Mister_G said:

The problem with the Honeywell one is that the motor is continuously in the stalled condition.  It only uses a few watts but is powered all of the time.

I would have thought most three-way valves work like this, including the Danfoss one discussed here. The only exception I've seen is one that Sunvic do, where the valve is driven to the different positions by a motor, with internal electronics that allow standard "dumb" wiring from a typical central heating controller. Opinions are divided about the reliability of these, but they save power as they are only powered when the valve is moving.

See http://www.seered.co.uk/sunvic.htm for a discussion of this type of vale.