HOW CAN I FIX MY BAXI SOLO 2 40PF BOILER?

Hi,
I just changed the circuit board on my baxi, but it still wont light up.
The problem started when i noticed that when the hot water & heating wont light up together.
(Could it be the timer ST9400C ..??)

When turned on the lights show "Boiler & Fan" & there's a faint humming sound (fan maybe).

Any help would be nice.
Thanks for taking the time in advance.

James
December 2011

could be fan. could be pump .may be air in system.

paul
September 2006