vaillant. no hot water in taps

[Agile]

I cannot immagine what anyone can do with an old design to "recondition" one. Nor can I ever think why someone would not want to buy a new part for their boiler.

Turn off the heating and let the boiler get completely cold. Run the DHW for several minutes and see if the heating flow pipe gets hot.

Tony

 

[mickyg]

like tony, I am really not sure how you would recondition this valve, not properly anyway. You can't get individual spares for the body, so at best its probably just been cleaned out which isn't gonna help. The original valve bodies like the one you have used a rubber which reacted with high levels of inhibitor and swelled, causing it to stick. Get yourself a new one!