mid position 3 port valve

[rmaone]

Hi, tried this question on plumbing and no success yet, suppose I should have been on this forum. Have a problem with my mid pos valve. When I call for HW, CH, or both, all works as it should. But from the mid position when I call for CH only, the valve stays where it is, heating water when not asked to.(hot rads = scalding hot tap water) If the valve is in the mid pos and I want HW only, this works fine. I currently have the HW, and CH programmed so as they don't come on together, but I would like this sorted, anyone have an idea. Thanks

 

[shaky]

It could be programer fault I would get that tested first.

 

[buckley plumb]

when you select heating only on the programmer do you get 240 volts on the white wire and the grey wire to the valve .

 

[lame plumber]

if the valve is moving ok it could be a faulty programmer is the likely issue as mentioned, unlikely to be a wiring issue if its worked ok before so just swap programmer like for like, but before doing so, test your cyl stat is clicking on and off ok to control the valve correctly

 

[rmaone]

Programmer is brand new, and yes call for hot water only, grey and white wires have 240v. I do have a hot water off wire installed. Checked the cyl stat ( brand new) I did find on cyl stat that when I have 240v on the calling wire I also have 50v on the satisfied wire. And when satisfied 240v also 50v calling?

 

[buckley plumb]

I would say valve then

 

[rmaone]

Why do I find 50v on the open contact side of the cyl stat? And would this amount be enough to hold the valve?

 

[BLOD]

Programmer is brand new, and yes call for hot water only, grey and white wires have 240v. I do have a hot water off wire installed. Checked the cyl stat ( brand new) I did find on cyl stat that when I have 240v on the calling wire I also have 50v on the satisfied wire. And when satisfied 240v also 50v calling?

Not sure if I've read this post right but with a call for hw only the white wire should not have 240v
and the grey wire should only have 240v when the cyl stat is satisfield

 

[buckley plumb]

Programmer is brand new, and yes call for hot water only, grey and white wires have 240v. I do have a hot water off wire installed. Checked the cyl stat ( brand new) I did find on cyl stat that when I have 240v on the calling wire I also have 50v on the satisfied wire. And when satisfied 240v also 50v calling?

on heating demand only grey and white should have 240 volts . hw only grey only live. remove programmer and link heating on and live and hw satisfied and live if it woks its the programmer if not the valve

 

[mountainman]

on heating demand only grey and white should have 240 volts . hw only grey only live. remove programmer and link heating on and live and hw satisfied and live if it woks its the programmer if not the valve

Are you sure?

 

[rmaone]

Sorry my mistake, yes on heating demand only, white and grey are both 240v

 

[buckley plumb]

Are you sure?

grey would be 240 if hw is satisfied or htg is off n programmer then should give 240 to grey hw off wire.if there Is 240v on grey and white when pogrammer is on heating only then the valve shoul move to hetng position. probably should not advise to short wires to test

 

[rmaone]

with water and heating being called for white and orange are live, and valve in mid position. With water satisfied the grey livens up , white still live but valve stays in mid position. From here I have to briefly cut the supply to the programmer, once back on the valve moves to heating only

 

[doitmyself]

with water and heating being called for white and orange are live, and valve in mid position. With water satisfied the grey livens up , white still live but valve stays in mid position.

Have you checked if the valve is sticking? Remove actuator to check.

The 50V you get on one HW stat terminal when there is 240V on the other is to be expected.

The grey and orange wires are connected internally by a resistor which drops the voltage to betewen 50 and 100V. This is to stop the boiler firing from the grey wire when the valve is held in CH position after CH only has been satisfied.

 

[buckley plumb]

with water and heating being called for white and orange are live, and valve in mid position. With water satisfied the grey livens up , white still live but valve stays in mid position. From here I have to briefly cut the supply to the programmer, once back on the valve moves to heating only

the orange should not be live when hw and htg is called unless hw is satisfied - to check for sure the orange needs to be removed from the wiring centre to check its not got 240v . in hw and htg mode the boiler sw live is fed from the cyl stat not the orange on the valve.without removing cables to check you will get back feeds

 

[Howsie]

If everything is brand new, who installed it?

 

[rmaone]

Many thanks for everyone's advice, have decided I need to get a man in. Thanks.

 

[AlexGas]

Once, I had to sort out a temperamental Lifestyle 3 port valve… After all the head scratching I’ve noticed that the valve head was touching the HWC foam insulation, in fact there was a good 4mm dent in the insulation. This valve doesn’t have the solid head base like Honeywell has. So the head was a bit of line – wonky and ever so often the motor just couldn’t cope with the stress.
Stanley knife came to rescue!

 

[AlexGas]

What's the make of the valve?