Is this a leak. Thermal image camera

[Thermal2020]

Old cottage was renovated 5 years ago, all new pipes underscreeded floor. This year started getting damp on the walls internally however it's an old stone cottage built of the ground over 100 years ago and half built block in the 1980s. A new french drain been installed all around the outside which is working great after checking the inspection
chambers after it's rained and a day later.

Still worried about the dampish looking spots in the screed although these have been receding once the heatings been on. Last tennant didn't use the central heating all over winter, only a freestanding wooden stove.

Called a plumber which has a thermal image camera and an ultra sound to find a possible leak however the heating wSnt on long enough for him to get a reading with his thermal image camera in his slot he had available. The ultra sound couldn't pick anything up because of the heavy laminated flooring and the underlay is what he said. So, I hired a thermal image camera out and checked where the pipes are. This is what it's reading but I don't know is it just the pipes and fittings showing or is it a leak.

Internet slow so can only upload one pic at a time.
[automerge]1600800067[/automerge]

[automerge]1600800470[/automerge]

[automerge]1600800679[/automerge]

 

[Thermal2020]

Forgot to mention that have asked 5 plumbers there opinions not and getting conflicting info. Some saying it's just the heat of the pipes plus the compression fittings without lagging heating up and another one saying ice has busted a pipe or pushed a fitting open when there was no heating in the cottage over winter.