vaillant 637 wiring mess

[psk]

hi,
I was asked to wire up a system by my mate who is GSR also. The scenario is we got a vaillant 637 system boiler heating up a megaflo cylinder. The wiring is incorrectly done because the room stat when satisfied turns the boiler off completely no pump overun atall.
the orange SL outs supply the boiler L in.
room stat is through timer to ZV live in. I cant remeber the terminal numbers im afraid.
can any of you wiring wizards please explain where are we f***ing up as my ol boss would say?
cheeers comrades

 

[moogwai]

Email vaillant tech for a wiring diagram....they'll send one through in a day or so. Thats what i do when i have a problem.

Sent from my GT-I9100 using Tapatalk 2

 

[grahamgas]

New or old 637?

 

[psk]

hi graham its the new 637
this issue has been bugging me for a few days now i would really love to tackle it....any ideas?
cheers

 

[grahamgas]

Check what d 019 is set to on the boiler.

 

[psk]

ok will do later today and get back to you. much appreciated. thanks