problem with a Vaillant VCW282e

[robwilk]

Hi
After the big freeze im having trouble with my old and trusty 282.
First the DHW works fine but when i put it for heating it shuts off.
My bro in law says its always the diverter valve that goes but on mine the diverter valve always drives to the right regardless of the position of the switch, which makes me think its the board controlling the valve rather than the valve its self.
As I can not get an bits or any one to look at it who might have bits I thought I would trawl the web for information and came across this site.
Any tips would be gratefully accepted .
thanks in advance.
have a good new year everyone

Rob

 

[Andygasman2010]

Don't listen to your bro in law, these diverter valves are very reliable. They are hydraulically controlled not electronic, this is done by the servo valve and water section. Which in your case is stuck in hot water position.

Right at the front/centre behind the grey pannel sits the servo valve. It's a black arm with a spring on it, and has a few small copper capillary tube going to it. This black arm hasn't returned to rest position propperly. Give it a nudge and you should see the diverter move fully inwards to heating position.

 

[robwilk]

Cheers andy, tried this and it was stuck but the servo valve does not move when the boiler is switched between DHW and CH.
is this supposed to move? would it be worth removing the spring and putting the lever in the opposite position as it is now to see if that returns the divert valve to the CH position.
any tips to prove what is wrong as its now pointing to the servo valve.

Rob

 

[Andygasman2010]

If the servo valve does not move when you turn on/off a hot tap then you probably have a faulty water section also.

Directly beneath the servo is a silver water section that contains a rubber diaphragm, it has most likely perished, this is available as a seperate part and is much cheaper than a complete water section.

I'd do this first, see how you get on. They're not the easiest of diaphragms to change what with screws that can seize and other awkward things so you might want to get someone in.

 

[robwilk]

Thanks again Andy, water section replaced and all toasty now.
your a star.
rob