Odd voltage readings on 3-way valve & heating always on with hot-water

[Johntheo5]

Where can you see the arrow?.

 

[ianmcd]

I cant but it is on the side of the pump body

 

[westhesmallholder]

Thanks all for the replies.

1. the black wire is in a loop, it is just for the motorised valve
2. the arrow on the pump body is pointing towards the 3-way valve
3. the pipes coming off before the pump and rejoining afterwards i believe are the heated towel rails in the bathrooms as they are always on and these head in the right direction
4. the 3-way valve is indeed a mid point one

When fitting the valve i have to turn the lever a bit (push forward) in order for it to line up with the valve shaft. Hence, i think that when the lever is in the middle position in it's track then it is in A (hearting only setting), when it's in the Manual position the valve is at mid-point/A&B (heating and HW) and the HM only (B) can only be achieved by the motor. i.e. i dont seem to have enough travel in the manual level to force HW only. Does this sound right?

 

[Johntheo5]

Its the spring return that "forces" the valve to HW position only, Port B only, the motor plays no part in driving the valve to the HW only position, when the lever is latched in then the valve is in mid position with ports B & A open, if the lever is unlatched, the valve, under spring return tension will return the valve to the HW position only.

 

[westhesmallholder]

sorry, yes, that is right. i keep confusing the resting positoin of the lever/ball, vs the flow of water (which is the opposite).

 

[RandomGrinch]

1. the black wire is in a loop, it is just for the motorised valve

Just to add...

That terminal block needs to be placed into a proper enclosure including strain relief for the cables.

An exposed terminal block, mains voltages, plenty of bare copper showing on the wires, along with the proximity to water and pipework, really isn't a good combination...

 

[Johntheo5]

sorry, yes, that is right. i keep confusing the resting positoin of the lever/ball, vs the flow of water (which is the opposite).

You are saying the heating comes on with the HW.
Can you get someone to watch the valve when you request HW only on (cylinder stat turned up as well) because the only way you can get heating as well is if the valve moves to either mid position or fully across to heating only, otherwise port A will not have any flow.

 

[cross thread]

Turn off the towel rails, to check if it’s causing the issue ,