how do i pressurize the expasion vessell on a 28i comb

[barneygallop]

hello,
is there anyone that can advise me wether its a diy job or do i need to call in the specialist,i have a worcester 28i combi boiler and the pressure keeps dropping to zero ,i have to fill it up everyday i assume after reading answers from other people that its the expasion vessel thats the problem,i have no leaks by the way,do i need to repressure the expansion vessel if so to to what pressure and how do i do it or do i need to call in the specialist, id be gratefull for any help what little is given,
many thaks
barneygallop

 

[Burnerman]

Dead easy so long as you can access the car tyre type valve to top it up.
When the system is completely depressurised, check the pressure in the EV and pump it up (car foot pump, bike pump etc) up to 10 psi.
Repressurise the system with the filling loop.
If you notice water at the EV valve, the diaphragm has split and you'll need a new EV.
If your pressure continues to drop, I'm afraid you have a leak somewhere....
John