New Worcester/Bosch 24i banging on valve close?

[zetland76]

Had this boiler for 3 months, works fine. I have a single hall thermostat which appears to control the boiler correctly. The gas appears to be roaring through the boiler whilst heating the house, but as it gets close to the set temperature there's a bang from the boiler (like a valve closing suddenly). I checked the green gas burning light expecting it to be out, leaving the circulating pump as the only noise coming from the boiler, but the gas is still burning all be it more quietly.
I'd love to known just what is happening in the boiler, if only for peace of mind.

Thanks

Mike

 

[adlplumbing]

not sure without looking but it should be under warranty call them out but turn it off to be on safe side

 

[rosiew]

get worcester out because boiler under warrenty