strange fault with baxi solo 2

[chris]

hi guys
ive got an odd fault with my baxi solo 2.

when its fired up its working fine...however it doesnt start on its own.

on start up, all the correct red lights come on:
boiler on
fan on ( and it is on. I can see it spinning)
pilot on.
I can hear ignition sparking but it wont ignite on its own from there.

I found , by accident, that if i undo the bottom two toggle clips from the combustion box door and lift it forward by a couple of inches , whilst the ignition is trying to light, it does ignite, all be it with a flash over.!
Boiler on light, then illuminates.
I put the cover straight back on and let it continue. All good

When its been going for 5 mins and has got hot , if i turn it off and back on, it ignites correctly and boiler will keep going properly until its swithced off and gets cold again.

I can get it going time after time using this method but cant understand why it wont fire up on its own.

so why does it need the box cover to be removed to start it?
and why, then when its hot , does it ignite properly?

any ideas would be appreciated.
cheers

 

[ShaunCorbs]

Time to call a gas energy out

Also don't undo / release the clips from the box door

 

[Harvest Fields]

Don’t remove any of the casing to the fan or burner unless you are gas safe registered. I would get an engineer out to repair/test.

 

[GE Sonny]

Potentially tracking to earth on the electrodes. Like the other two said, call a GSE out.