brakespear
Doctor Worm
Mine is exactly the same, pressure goes after 3 days and needs topping up but no leak has ever been found. And I've gad a new boiler fitted and the new one is exactly the same. Bizzare.
I had the same problem and had our annual boiler maintenance and had to have part of the meter replaced (regulator?) and maybe coincidence (because I can't see how it makes a difference) but not had the problem since.