Confused By 3 port Valve

[fouxdafafa]

I hope someone can explain to me what's going on with my 3 port valve and whether it's normal. It's an ACL Lifestyle midpoint. I have a programmer that allows separate CH and DHW. When I force it to DHW only, everything's fine in that the WMH indicator on the valve goes to W and the manual lever is to the left. When I try and get CH only, the WMH goes to H but the manual lever moves (by itself) to the right, as if in the latched position. If my understanding is correct, this position for the manual lever opens both ports, so despite trying to get CH only some of the hot water is going to the DHW as well. I think this is confirmed by the fact that the pipe to my HW tank is warm, although not quite as warm as the CH pipe. I've tried pushing the lever back to the left but there is too much resistance. Can anyone explain?

 

[kittedup]

How old is the valve?

Sometimes they can let a small amount "pass" if they get old or the system water is dirty.

Even when it's working correctly the pipe will get warm though- it picks up the heat from water passing through the valve.

Is the pipe warm coming out the bottom of the cylinder?

Ted

 

[fouxdafafa]

Not sure how old the valve is - we haven't owned the house from new. Pipe from bottom of HW cylinder is slightly warm.

I understand your comments, but I'm more baffled by the movement of the lever to the open position. Is this normal?

 

[twgas]

It's normal, the man lever is connected to the valve/motor so always moves with it.

 

[fouxdafafa]

It's normal, the man lever is connected to the valve/motor so always moves with it.

Ah, OK. Thanks for that. So does it make sense that the lever goes all the way to the right, which opens both ports, when only CH is on?

 

[twgas]

When only the CH is on the HW port (B) should be closed.

 

[fouxdafafa]

When only the CH is on the HW port (B) should be closed.

Any suggestion why it would be opening both ports? Or is the obvious answer that the valve is buggered?

Is it possible to take the lid off these valves and have a fiddle?

 

[twgas]

If it's only going to mid position it may be because there is no HW off connected from the programmer to the grey wire of the valve.
Does it go all the way if HW is on at the prog but turned low (satisfied) at the cylinder stat?

 

[fouxdafafa]

So what you're saying is it's normal for the manual lever to go all the way to right i.e. the midpoint position, not just when you manually move it there. You may be correct about the wiring - I haven't been able to verify that. What's still confusing me is that when I'm on heating only, the indicator on the side of the valve goes to H (not M) but the manual lever goes to the right - the both ports open position. Does that make sense?

 

[twgas]

I think you're taking too much notice of the manual lever, the indicator on the side is much more relevent.

 

[fouxdafafa]

I think you're taking too much notice of the manual lever, the indicator on the side is much more relevent.

OK. The indicator on the side behaves as expected. I still have my suspicions though that when CH only is on, some hot water is making its way to the HW circuit. I say this because the pipe to the cylinder becomes warm after a while - not hot, just warm.