central heating not coming on , changed 3 port valve

[EliteHeat]

You should have seperate grey and white wires!

Anyway, the reason your heating isn't coming on is 'cos the voltage to both white and grey are insufficient. You should get 240v to white with CH on, if the HW is off you should get 240v to grey.

I'm not a MV expert but I believe that the voltage yuo are getting is insufficient to power the valve and operate the microswith to fire the boiler. I expect someone will tell that I'm talking crap though!

 

[Bamber gaspipe]

Wired up incorrectly, don`t bother a spark they are useless when installing heating controls, speak to an Engineer, most of them have Sparks to install & certificate their work,

 

[2face]

the grey is not connected to to 7 in the 10 way and 2 on the cylinder stat., this stops the lever going past the 1st micro switch and engaging the second .!
live to the white, nothing to the orange ......
if u manually pull the lever to engage the second switch it fires up .

the grey should be live and needs connecting as to the attached diagram . pm me for any help m8

http://www.acv-uk.com/images/pdfs/etechw_tech.pdf page 24 pdf