worcester combi 24i rsf not firing

[topbanana]

hope for some assistance please.
my friend has had a leak in a down stairs radiator valve.
i replaced the valve and he fired up the boiler and everything appeared ok.
next morning he had a leak within the boiler,and found it to be the automatic air vent, which he replaced.
however, he repressured the boiler without drying it out and turned it on to hear a large bang.
i got there to find the fuse had tripped at consumer unit and blown within plug. the fuse had not blown within the boiler.
all of this was reset and the boiler now dried out at circuit board with a hair dryer.
it was pressurised at 1.5, pump screw removed for bleeding.
the boiler was switched on, light came on.
heating was switched on, fan spun, pump felt vibrating.- no ignition or sound of ignition.
reset button on top of boiler,(brownish plastic cross),was pressed but didn't feel as if it had been tripped.
water when requested has the same response- no ignition.
all leads have been checked, only one lead was dislodged while drying that was the pump lead which was returned brown to live, the same way round as the other leads.
i'm worried it might be the board, is there anything i've missed?
for info,the boiler is situated at the high point of the system.

 

[ollski]

Aren't there 2 fuses on the board and a 24v transformer?

 

[topbanana]

thanks for speed of light reply.
in answer- not sure, but would any other fuse or transformer just affect ignition?

 

[ollski]

I'm not exactly sure off the top of my head, but I would check everything as you will almost certainly have a mullered board. Take all the connections off and dry inside them and the board, check the fuses and make sure the air pressure switch is switching across. I have 3 or 4 in my van that failed due to the aav soaking them which I am holding onto in the faint hope they may dry out over the months.

 

[topbanana]

hallalooya. i think thats how its spelt!
he gave it a go this morning before i got over to proceed and it worked.
something perhaps had dried out overnight.
thanks very much for your help ollski.