neighbours boiler fuel keeps banging, is it safe?

[Gilly]

neighbours boiler fuel keeps banging, is it safe?

[woofgang]

what boiler fuel is it?

[Gilly]

dont know, but every now and again we hear an almighty bang, they know about it as it has made the lady jump quite a few times but its a bit scary that it may take the wall out one of these days

[firewatch]

sure its the boiler flu? it may be water hammer where there is an air lock in the pipes or something we have itx

[Gilly]

its coming for the flue on the outside wall

[boxtops]

You said fuel, I thought it was the oil making a banging noise....

[Gilly]

this has been going on for about 2 years,I initially had it in my mind that it was someones cat flap snapping shut until my husband pointed it out,but seems to be getting louder and more frequent, must try and have a word as it is now started to affect our sleep as it happens though the night as well
Thanks for your help

[bookbinder]

I once had this happen in a gas-fired boiler. It was then 25 years old, and the gas fitter who came to examine it condemned the boiler. It happened when the boiler burners were ignited. Something to do with 'pre-ignition', I believe. We had to get a replacement boiler, and the gas man said that the new one wouldn't last anywhere as long as the old one.