Worcester Greenstar Ri Boiler Knocking

[Asgeir]

Hi there,

My boiler (Worcester Greenstar Ri) has started making a soft knocking noise when it turns on, and again a few times when it turns off. I've attached a short video of the sound. It isn't constant, it seems to happen within the first 10 mins of the boiler starting up, then you won't tend to hear it again. The radiators are still getting hot and the hot water is heating fine too. I will say it does seem to be a little worse when it's just the central heating running as opposed to just the hot water tank running.
As it's a new sound, im just curious if its the start of a bigger problem?

Thank you

 

[ShaunCorbs]

Sounds like pipes expanding eg contraction and expansion on a joists

 

[Asgeir]

Sounds like pipes expanding eg contraction and expansion on a joists

Thanks for the reply Shaun. I hadn't thought of that possibility, but after checking out some videos it does sound very similar. Is there any particular reason why the sound is only around the boiler, I've checked through the house, by radiators, and I cant hear it anywhere.

 

[ShaunCorbs]

Thanks for the reply Shaun. I hadn't thought of that possibility, but after checking out some videos it does sound very similar. Is there any particular reason why the sound is only around the boiler, I've checked through the house, by radiators, and I cant hear it anywhere.

Could be right above the boiler pipework or the boiler pipes internally expanding etc