honeywell v4073a HELP PLEASE

[sfechalky]

Hi guys have a honeywell v4073a valve this is now the third one thats been installed on my system in as many weeks. the problem is that the CH is still calling for heat when everything is off. Even with the valve wired with just the grey,blue,green, cables connected
there is still 150v back feeding on to the white and orange cores which when connected is still enough to drive the boiler. changed 2 valves and 3 heads. And they are all the same is there a bad batch? as all is ok with everything else.

 

[mickyg]

what makes you think its the valve? what boiler is it? GW micron by any chance?

 

[sfechalky]

Because with the valve connected to the wiring center and the white and orange cables removed from the terminals i am getting a voltage of 150v on the orange and the white. if i connect a switch to the boiler and manualy switch 240 to it it works fine when 240 removed the boiler shuts down as it should. the boiler is a buduras 500 24s. all works fine for HW.

 

[seco services]

you will get about 100v on the orange if the grey has 230v to it.

 

[sfechalky]

still seems quite a high voltage 150v but how can i rectify this as all that was wrong with the system before was the valve was stuck between HW and CH so i freed it up with some pliers but after 3 months it happened again so i replaced it with this Honeywell one. the back feed voltage is enough to drive the boiler. i think the original was a draton.

 

[Hugh Jaleak]

I'd double check all the wiring, may be a wrong connection giving a rogue feed somewhere. Good wiring diagram here: http://octaveblue.co.uk/c_heating/index.htm

 

[sfechalky]

wiring all ok the back feed is there when its dis-connected with only the grey CH off cable connected and Neutral / Earth the CH off should be at 240v in this state 0v-45v on white wich is call for heat and o-45v on orange which is call to boiler. if i take the motor head off the valve it all works fine.