Worcester28 boiler stopped

[foxhole]

Boiler stopped running at the weekend, can still here it clicking when timer turns on but not firing up.
Thought I would check out the flue as my granddaughter has a habit of poking toys in holes .Looking into it I can see what looks like a resin circle at the back of the flue with a small hole thru it about the size of a 5 pence piece, is this what it should look like, strikes me as a tiny hole to vent the boiler?
Will be getting it looked at by installer , just curious about the flue design.

 

[stardanny]

You will need a gas reg engineer in to look at. The hole ( is it above boiler on bend piece? ) should have a screw cap to seal it.

Daniel.

 

[foxhole]

No, hole is visible looking into the flue with a torch.