Downstairs rads ON despite controller panel status shows OFF

[ezeqiel]

Hi all,

First time poster, but have done a fair bit of reading in search of information previously.

My problem in a nutshell (albeit a large one) -

Oil fired central heating
External boiler
Pumped System

I've a 3 zone/channel system in placed controlled by a Horstmann H37 XLPlus controller panel, heating downstairs rads, upstairs rads and water seperately.
Currently, when mains power is on to the H37 controller despite all zones showing as off, the outside boiler is firing and heating the downstairs rads.

Upstairs and the water remain off but do function as expected when using the controller.

2 Myson Power Extra motorised valves control the flow for downstairs & upstairs zones. When the boiler is firing despite the controller showing all OFF, no operating lights are shown on the downstairs Myson valve despite water continuing to circulate through the downstairs system.
Turning the controller on (and with the room thermostat turned adequately down) the operating light on the Myson will show on as expected. Turning off the downstairs system via the controller, switches the operating light to off on the Myson valve and you can hear the mechanism within make its typical whirring noise as it stops. The water in the downstairs system continues to be heated however.

The outside boiler is not constantly on but does still regulate its temperature itself, so it does continue to cut in and cut out as it feels necessary for the duration that the mains power is on.

So my question is whether I have a faulty controller, faulty downstairs Myson valve or is it a combination of both?
Or is the fault likely between the controller and boiler itself?

(apologies for the long post, but trying to provide as much information as possible)

Any information or ideas appreciated!

Thanks,
Ciaran

 

[swbjackson]

Do you have frost protection?

 

[ezeqiel]

Do you have frost protection?

Frost protection in regard specific elements of the system I've outlined already such as frost protected thermostats or do you mean in general, i.e. pipes below the frostline, lagging etc?

Forgive my complete lack of knowledge in the area -but I can say my water system is an unvented indirect system, which I understand is a level of frost protection in itself.

Is that of any use to your question?

At the time that this issue has occurred (day before christmas eve) we'd not had a any frosty weather preceding it if that is of any help.

Thanks,
Ciaran

 

[HH1]

Posible problem :-
The downstairs Myson valve sounds as if it is passing water through, this could be down to not moving its full travel to "off" position, or when it is fully off the water still gets through, thus heating your radiators.
If the valve is not in its fully closed position there is a possibility that it is still "sending" the signal to the boiler to fire (or there is an additional problem where the boiler is getting the signal from elsewhere).
Would certainly look at this valve first to see if it is:-
a)fully closed
b)sending signal to boiler
c)passing water
From the info given it sounds as if its not moving fully to off position.
Controller sounds to be ok (so far).