Valliant VCW GB242EH no heating

[bonesy60]

Went to one of these today hot water works fine but no heating boiler lights runs about 10 to 20 secs then cuts out. The hot water circuit is very hot the pump, and plate exchanger and the Dhw diverter on the front are all hot. But the flow stays completely cold

[so-solar]

could well be the diverter valve mate!

[bonesy60]

Are they separate on these boilers

[puddle]

is this the old 242e from the early ninties with door opening sideways at bottom and gray metal panel covering control box held in with two side screws ?

[bonesy60]

Yea that's the one the main diverter is under the pump but the dhw one is at the front I think.

[puddle]

could be divertor stuck but think the problem is the black plunger above the water section at the front of the boiler ,a common fault is it sticks in the up postion on hot water micro switches
If you open boiler look above dhw diaghram section you will see the black arm in question when tap opens it lifts and moves servo unit as required,when tap closed it should return to required position for heating
with taps off push down arm and heating should start working,if so remove arm and clean and greese pin sleeve underneath

[bonesy60]

Would this case the water not to flow through the central heating circuit cheers Ian.

[puddle]

Originally Posted by bonesy60

Would this case the water not to flow through the central heating circuit cheers Ian.

If black arm not seated back down correctly divertor valve will not be able to move to heating position
you will see a small servo valve behind black arm with small tubes going to it,as it moves pump flows water through the small tubes altering divertor valve position

[bonesy60]

Ok will give this a go tomorrow many thanks Ian.

[bonesy60]

Went back to this boiler last night Dhw diverter arm was stuck in the up position pushed it down turned the boiler on and the heating worked. Stripped it out cleaned and greased put back together and the arm was returning but would not pull the main diverter down on the the micro switches. I had all the control tubes of and cleaned them out could not get the diverter apart cause the pins had seized so I think I will just put a new one in thanks for all the help Ian.