Hello,
(sorry for my bad english, Google does help me a little)
I think you're right.
The dripping comes from the valve, sometimes a piece of Calcium washes during the descale into the valve and stuck
It seems that the sealing is calcified or damaged. Try to remove that piece by very slowly opening the valve, so that the pump starts before the valve opens, try it several times.
You can also try to disassemble the valve and place its parts in descaler (maybe overnight but see your descaler-instructions).
If nothing helps, you need a new valve pin.
Take a look at
[url]http://www.partsguru.com[/URL]
best regards
hope dies last - but it dies!