Vaillant VCW GB 221 H Problem

[lukeuk]

I been attempting to fix one of the above boilers, there is central heating but the boiler does not fire when a call for hot water is made. I noticed that the servo valve/switch was not connecting and was advised by vaillant that i should replace this part, after doing so there is no improvement, the spring raises the arms but not enough to hit switch..

any ideas?

 

[Gasguru]

Don't listen to technical desks...they are often wrong

Might want to check the diaphragm instead.

 

[lukeuk]

Thanks for your reply!
ive just noticed that you can ajust the switch body via the screw.. if that fails ill check out diaphram.

 

[Bunnyman]

Don't bother with adjustment it won't help change diaphram

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[Homesafe]

These VUW VCW etc. boilers, are they as hard as they look, to work on.

Cos they frighten me sometimes

 

[lukeuk]

Ok thanks Bunnyman, ill check it out

 

[kevplumb]

limescale also causes the problem