50/50 ... that being said I wouldn't expect a pipe to be there unless there was a hangover from a rad that was previously behind the door.
this is the room the other side (kitchen). The detector went red when put on spot for drilling.Good point - what is at the back of the wall?
It’s unlikely, but not impossible. Thermal imaging camera may help or as Harry suggested.

Yes, I think you can hire them.Can you get them?
Some of the Caterpillar android phones have IR cameras.
You can pick up an old S60 for as little as £150 on ebay from time to time.
A "council" employed plumber in my local says his is really useful for finding underfloor heating pipes.
I dont rely on my detectors totally. Seem to beep all the time and you end up thinking you cant drill anywhere
They pick up nails screws and cables too. Basically you search for a possible linear feature.
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