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Mid Position Valve Not Switching - No CH?

Hi,
Need some help with the below.

I have hot water, but no central heating. Common problem you say, but i have some strange readings across my mid position valve.

The valve i have is the Drayton mid position valve, as mentioned above i have not CH but plenty of HW. The valve seems locked to the far left hand side, whether i turn the CH on or off the valve stays locked.
I have had the valve apart and everything is fine, no signs of damage and manually it actuates.

With everything looking ok, visually, i have tested, the results are below.

CH ON - Orange 240v White 240v Grey 66v & Blue 0v
CH OFF - Orange 240v White 26v Grey 12v & Blue 0v
HW ON - Orange 240v White 26v Grey 12v & Blue 0v
HW OFF - Orange 240v White 26v Grey 12v & Blue 0v

Strange readings?? I have tested this with 2 meters now and still getting the same results.
I have now taken the mid position off again and manually turned it to the far right, but upon putting the CH back on it drives straight back to the far left.

I dont wanna pay for someone to come in and resolve for me so your help in this matter would be greatly appreciated.

Many Thanks

Wayno678
March 2009

Drayton Heating, Home Heating Systems Switching Help Hot

you cannot replace syncron motor on drayton , you require valve head... your reading aren't OK...
1. when HW off or satisfied by cyl' stat this puts 240 v onto grey wire this then moves valve over to close off port B stopping water going to cylinder.... looking at your readings above you don't have 240 v on grey at all.
2.white is feed from room stat... so if you turn room stat up and down this puts 240v on/off to white
3. orange is feed to boiler and pump, so 240 to orange means pump/boiler on

papmcg
March 2009

The valve is barely a year old, but i suppose i have the CH switching on and off 3 times a day and well they aren't the most solid of valves..

Thanks again, will keep updated.

wayno678
March 2009

Ill try that tomorrow...Thanks Steve

Wayno678
March 2009

Nope your readings are fine
replace the syncron motor in the Drayton mid position valve

justeve
March 2009

Thanks Marty,

Ive checked the motorised head is working correctly on top of the valve.
Room stat doesnt click on when required. I have recently changed this, unsure if i have correctly wired.
Drayton roomstat+, red, yellow and blue wires, any ideas?? Got ON OFF COMMON & N...Dont really wanna cause fuses to pop.
Ill try and read up.

Thanks again

Wayno678
March 2009

make sure room thermostat is working ok ,calling for heat etc, check actuator .motorised head is working on top of valve

marty
March 2009