First time homebuyer and first time poster. I'm looking for some guidance with a fairly loud buzzing noise our boiler is making. We've been in the house about 2 months. The boiler is pretty ancient but it still heats the house quite well.

It's always made a bit of a buzzing sound, but either the sound has gotten louder or now I'm more aware of it. Either way, I wanted to get some thoughts on what it might be and cost to fix it.

We made a video of the part that is buzzing.

Thanks so much!