In article .com,
wrote:
My domestic Central Heating Pump is running continuously despite the
fact that the CH mode on the Landis & Gyr mini programmer is switched
off. The only method of switching the pump off is to disconnect the
electrical supply at the local junction box. Not a particularly good
method.

You should have a method of isolating the heating electrical circuit. A
double pole FCU is the normal way.

Can you point me in the right direction please and advise the heirachy
of the control system. By this I mean, does the programmer have the
sole control of the central heating pump by virtue of the CH mode?
The system also has 2 off 2 port motorised valves.

Since that sounds like a fully pumped system, there must obviously be
(auto) switching between the room stat and cylinder stat in their control
of the pump. These are commonly microswitches operated by the valve and
can fail, or the valve isn't moving to the full extent to operate the
switch.

Other possibility is the boiler controlled pump over-run circuit if there
is one fitted.

--
*I have my own little world - but it's OK...they know me here*

Dave Plowman London SW
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