I’m currently living in a flat in a 1930s block on the top (2nd floor) of the building.
There are noises from the ceiling which I initially thought were the pipes in the central heating system expanding, but they are near-constant – it’s not like they happen when you turn the heating on or off. It’s not pipe hammer. If you can imagine a cross between the noise expanding copper pipes make and the noise of a fan catching its housing as it rotates faster and faster and then slows down. There is a combi-boiler.
Can anyone diagnose what it is? It’s not my house so not my problem to fix but it’s keeping us awake at night.

tv aerial wire resonating in the wind and tapping the roof?
Aerial mast resonating in the wind?
Gutter doing them same?
Id be surprised if there are any pipes up there

I have nothing useful to add.

Are there any extractor fans, for your property or others below you?

Squirrels digging about in loft insulation/lagging?
see if you can see any holes or potential routes in under the eaves?

They’re little shits if it is fluffy rats the land lord really needs to know.

it’s not an animal, the noises are too rhythmic, and for the same reason I don’t think it’s aerials or guttering.
we don’t have an extractor fan, but others might and I did wonder about this as it does sound like something rotating.
maybe I need to see if I can get onto the roof.

anyone any ideas? I can’t think it would be anything other than the central heating pipes, but why is it so rhythmic and why is it happening so much?

Got to be either a ghost or the bogey man

Turn off you electric at the meter- see if the noise stops. If it does try turning the power back on one circuit at a time. But given that its a flat in a larger building theres every chance the noise is coming from a bit of hardware belonging to someone else.

Spinning chimney cowl?