Radiators Warm When Water only selected

[vertigo]

Hi
I get warm radiators when Water Only is selected
I changed the 3 Port Valve but still the same, I changed it again as I thought I may be unlucky and had a faulty one but just the same happens.
I have checked the wiring and when Water, Heating, or Both are selected the valve moves to the correct position to shut off that circuit, or opens both for both
The valve I have is a Hortsmann 322xl
I have Hot Water Cylinder on landing, the Expansion tank is in the loft, the pump is half metre above the valve and I have turned this to power level 1 as I just thought that the water was pumped too hard and being forced through the closed section but is just the same

I am no expert so wondering if anyone has any ideas, my first thought would have been the valve (which I have replaced) or did I make a mistake with this particular make?

 

[ChrisR]

All warm, some warm, just the bathroom, llittle bit warm or bloomin hot?
New problem? Try closing the bathroom rad - really.

 

[vertigo]

Seems to be the rads nearest to the valve, ie upstairs and gradually get to a warm stage

 

[chrishutt]

Could it be reverse circulation caused by the return heating pipes not all being joined before the cylinder return junction?

 

[ollski]

A to heating ......B to bath?. ie is it the right way round?.
The simple check on these is to leave it all off all night, turn on hot water in the morning and feel if the heating pipe warms up. You will be able to feel which direction its heating from.

 

[vertigo]

Thanks, not sure how I would check for reverse circulation
Direction flow is correct as suggested above
Also forgot to mention it's not a new problem, inherited it with house so I don't know how long been like it
Also the Water flow pipe gets warm when Heating Only
Would not surprise me if something is plumbed incorrectly since so many problems with house (built 1983, and every neighbour I have spoken to says the same) in that seems to have been built by cowboys.
It's not a major issue, just annoying during the summer when all I may want on is the water

 

[ChrisR]

When you "changed the 3 port valve", did you change the brass(body, = valve) part or just the head/plastic part?
Odd that two should "let by".

Ah - a thought - check that your pump's the right way round. You're looking for an arrow on the pump. The pump should pump towards the centre connection on the valve.
The boiler cares too - later on that one!