Worcester 30i ionisation fault

[mutley racers]

Hi all. I hope you are well. Need some advice on this boiler and fault. E229. Went there and condensate was totally blocked so cleaned it and still not fixed. Then serviced it and still got the fault. Called up worcester and one says its the gas valve as it is making a 3 whoosing noises while trying to start. So removed gas valve and got a little bit of black dust and put back still not fixed. Called worcester again who said to cover the grey air intake pipe 3/4's to see if it starts and it did. He said if it stops again it could be the fan.

So had a call today saying the fault has come back. Now I don't want to have to buy a gas valve and a fan. Has anyone experienced this fault before?

Cheers