Ok, every so often (every other day at the moment) but mainly during the colder months (I think) we hear a noise during the night that is loud enough to wake from sleep, and is now affecting me (light sleeper) as well as my 2 year old son.
It seems like a vibration, not dissimilar from a washing machine starting a spin cycle. However, it does not appear to be coming from my house.
We are semi-detached, but ive tried pressing my ear to pretty much every section of adjoining neighbour wall and the source of the noise gets no louder.
At its worse the noise repeats roughly every minute and lasts for 15 to 20 seconds. Its also capable of shaking our bedroom door if ajar.
Our heating and hot water system is deactivated at night.
It woke me at approx 2:30am this morning, and my son at 4:45am. It finally subsided at 6:15am roughly. Ive had no more than 6 hours sleep total in the last 72hrs and I need to quash this noise.
Short of entering our loft to check, the only thing I can think of is some kind of top up to a water tank?, maybe pipes vibrating somewhere?
Failing that, despite not being able to source the sound through the wall, perhaps the neighbour is on economy 7 heating?
The trouble is, we are not on talking terms with next door and the very last thing I want to do is knock on their door, I imagine if they are the source there is very little they would or possibly could do any way. They somehow manage to sleep through a god awful big ben clock chime from their hallway every 15 minutes which also wakes me up on occasion..that and their yapping dog.
Having said that I did hear them stir at around 4:30am making me think this vibrating noise also woke them.
Does anyone have any idea what could possibly be causing this or what I should check?. Any serious suggestions welcome as its now becoming unbearable.
My latest theory is a secret underground railway network..

