Constant wet spots on carpet

[Lookingforadvice123]

Hi all

I wonder if anyone can help with my conundrum, Google hasn't hekped at all! I'm 8 weeks into living in my new house (1970s ex local authority, if it matters). In the spare bedroom there are five small wet spots on the carpet, which I originally thought was where a friend spilled a glass of water back in December but over a month later and they haven't dried, are wet to touch and won't dry even with a hair dryer on them! They're very small, and are close ish together, they look like five on the face of a dice. They're almost in the middle of the room so not a leak from the window or bathroom. Ceiling above is bone dry always, no signs of leak at all. Thought it could be condensation from the kitchen but the spots are actually above the living room, and again the ceiling in the living room is bone dry.

I'm stumped!! Any ideas?

what route do your central heating pipes take?

Is it definitely water?

Not 100% sure it's water but it certainly looks/feels like it?! And I've got no idea about the direction of the pipes I'll have to look at the property deeds if they're on there.

could it be oil, shampoo? rub a bit up with kitchen roll and see if the roll dries out or stays greasy.