Testing 3-way valve

9 Oct 2009
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United Kingdom

I had a 3-way valve V4073A fitted a year or two ago. When there is no power or the hot water is on the lever is in the B position for diverting water into my hot water cylinder.

However if I turn the cylinder thermostat down, and the central heating control up the lever stays in the same place. Should I be able to see the lever move over to central heating position, if it is working properly? I have a 5 wires for the valve, with grey and white wired together.

When I move the lever over there manually with CH on there is no resistance and it stays. When I turn off the CH and just have HW on the lever springs back. This looks as though there is an energizing voltage getting through, but it doesn't move the lever across by itself.

My water seems a bit hot - it was over 62 Celcius, when the tank thermostat is set to 55. I don't generally run HW with no central heating, because I just use the immerser.

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I have a 5 wires for the valve, with grey and white wired together.
shouldn't be wired together.

if the grey/white are wired together from the room stat and you have heating/hw on together at programmer you won't get hw to cylinder till heating is satisfied and the power is lost on the grey.

I have a 5 wires for the valve, with grey and white wired together.
shouldn't be wired together.

I seem to have both HW and CH, certainly the radiators were warm and the tank water was hot. Not having enough hot water hasn't been a problem yet.

It doesn't look good: the wiring pdf I saw said grey and white both 240 means CH only. Grey only 240 means valve hold in last position. White only 240 means HW+CH. The original system is over 20 years old. I don't know what the original wiring was. If I have time I may work out the wiring.

Do you know the answer to the question I asked: "should I see the lever move across for CH?"
you will not see the lever move

if valve powered up the lever arm will be floppy with no resistance
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the lever isn't a guidance to the position of the valve.
it's only a means of putting the valve in mid position when refilling the system etc.

as for original wiring.
white to room stat call
grey to cyl stat satisfied/programmer hw off.

beat yer ;)

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