hidden surprises lurking beneath your heated floors?

For anyone who has dealt with one, what first raised suspicion - and was there an obvious sign, or did it only become clear gradually?

A gradual, unexplained pressure drop or a damp patch that keeps returning could raise suspicion. Either would be a reason to investigate, not proof on its own that there’s a leak under the floor.

Does the possibility of hidden pipework make you think differently about your heating system, or do you prefer to focus on observable changes rather than worry about what you can’t see?

I’d lean toward focusing on observable changes rather than worrying about pipework just because it’s hidden. Recurring signs would still be worth investigating, but they wouldn’t prove there’s a leak.

If a change kept recurring, I’d see that as a reason to start with a proportionate, non-invasive assessment rather than jump straight to opening the floor. Hidden pipework alone wouldn’t be enough to justify that disruption; the next step would depend on what the assessment found.

If the pressure drop kept recurring but there was no dampness, I’d still start with a proportionate check - not assume there was a leak. I’d first want to know whether the readings were genuinely trending down under comparable conditions; the absence of a visible patch wouldn’t settle it either way.

A simple dated note can make that comparison clearer: record the pressure reading and whether the system is in a similar operating or cool state each time, and note any top-up. A repeated downward pattern under comparable conditions is more meaningful than one isolated reading, though it still wouldn’t identify the cause by itself.

Has anyone here had a hidden radiant-heating leak or corrosion issue confirmed? What finally established the cause, beyond the pressure drop or damp patch that first raised suspicion?

I can’t add a firsthand confirmed case here. Generally, recurring pressure loss is a clue, not a diagnosis: a heating professional would need to check whether the loss is actually in the heating circuit and investigate further to locate its cause. Confirming corrosion would likewise take evidence of the affected material, not just a damp patch or falling reading.