Alpha CB25 mystery of the vanishing hot water flow

[Gas Man G]

Hi chaps, would appreciate anyone could help me solve this, because this boiler is doing my head in.
Alpha (piece of £$%&) CB25 combi.
I've replaced the plate heat exchanger 3 weeks ago. Since then the hot water pressure has gradually reduced to a mere trickle. So you would think a block in the heat ex.
I removed it yesterday to check the flow through, but there's no signs of a blockage.
Under the tap the water gushes through it no problem.
Cold water inlet filter is clean & mains pressure good up to that point
The diverter valve is only 3 months old and the flow restrictor has been taken out.
Yet on the hot water out directly underneath the boiler the hot water has no pressure and therefore the restriction has to be inside the boiler.
I'm not getting anywhere with this one. Very nice client has no hot water. Frustration!
Anyone with ideas? (Yes the whole bloody thing should be replaced I know that already)
Cheers

 

[AlexGas]

Are you GSR!?

 

[gasmanrob]

Would love to help but we can't discuss gas related problems on an open area we have a private area for that where joe public cannot see and therefore cannot attempt. I'm sure you understand.

Introduce yourself and send your gas details over to a moderator and you'll be good to go in 10 posts time

 

[Ch4 plumbing]

You will need to get your post count up to ten then pm your GS details to Gasman to receive any answers to gas related questions.

 

[Gas Man G]

OK understood. Pity I can't get on sooner.
Who do I send my GSR details to & how?
Thanks guys

 

[Atouchofgas]

http://www.ukplumbersforums.co.uk/g...ic-forum/82396-entry-into-gsr-only-forum.html