Probable leak.

[Doggit]

Just what sort of hot water tank have you got. If you were to turn off the cold mains, or tie up the ballcock on the cold water storage tank, so that water couldn't flow through, then the leak would slow down.

The Pressure in the CH will rise as the boiler starts, then then sink back as it cools, so no problem there.

 

[DeanInEssex]

Daft as it sounds have you put your ear on the tile and listened for flowing water?.

Where is all the water going?, you'd surely have a damp patch somewhere I would have though.

Is there any chance of electricity cables run under the bathroom floor?.

Not daft at all, Ive already ordered a cheap stethoscope from Amazon, should arrive in the next day or so, I'm into my classic cars so it should come in handy. Its a downstairs shower room, and I haven't been over there yet (sods law we are both unwell), so Ive no idea where the water is going, I'm presuming its soaking away as she hasn't found any water in adjacent rooms. I'm just doing this by guesswork at the moment until I can get there in the next couple of days. Electric cables........its entirely possible. Apparently there is no sign of any water or other problems, just a very hot couple of tiles.
My immediate plan, if I cant see anything obvious, is a grout removal tool, try to get the tiles up without breaking them, cold chisel and lump hammer hoping its a thin screed and not 6 inches of concrete, and seeing what I'm up against.

 

[DeanInEssex]

Just what sort of hot water tank have you got. If you were to turn off the cold mains, or tie up the ballcock on the cold water storage tank, so that water couldn't flow through, then the leak would slow down.

The Pressure in the CH will rise as the boiler starts, then then sink back as it cools, so no problem there.

Not a scoobie until I get over there and investigate hands on. Heres a partial pic if that helps.

 

[Doggit]

Not sure, but I thinks it's an unvented cylinder, in which case, you need to turns the mains stop cock off to stop water flowing through it.

 

[DeanInEssex]

Not sure, but I thinks it's an unvented cylinder, in which case, you need to turns the mains stop cock off to stop water flowing through it.

Well as the hot tiles didnt cool down when the boiler was shut down for a couple of hours, even when all rads were cold, Im guessing that the leak is coming from the feed from the hot tank to either the shower or the sink, so my first test was going to be shut boiler down, and run hot taps until they run cold, then see if tiles cool down. That way I at least know what line is leaking.
I appreciate everyones help by the way, putting yourselves out to help a complete stranger..........cool.

 

[dilalio]

If she’s on a water meter just take a reading and don’t run any hot or cold water for a few hours and then check reading again.

If there is a leak and it’s big enough... you’ll see the meter moving.

Edit: any new carpets and door thresholds installed recently?

 

[Nige F]

My immediate plan, if I cant see anything obvious, is a grout removal tool, try to get the tiles up without breaking them, cold chisel and lump hammer hoping its a thin screed and not 6 inches of concrete, and seeing what I'm up against.

I don't think you'll be able to get any tiles up without damage so go for the leaking shower mixer option first. Maybe even claim on the house insurance and do nothing yourself ?

 

[DeanInEssex]

Well I think we can safely say there’s a leak. I’m on my way there now.