Stain on tiles - what could it be?

darrenheaphy

Hi all, we're in our home 10 months now and still super paranoid about spotting things and worrying so bear with me :rolleyes:

We noticed today a grain watery looking stain on some tiles in the hall. We're honestly not sure if it had always been there and we're now only noticing it or whether it's appeared recently. We've underfloor heating so am paranoid it could be a leak or something but I would presume the grout between the tiles would stain too? I've knocked on each tile and they all sound the same (as opposed to a hollow or wet sound).

We also speculate that perhaps the stain was there from construction times and a puddle from rain or whatever would have done it.

Some pics:

Carlow52

The second picture suggests to me that u have a leak: it looks like the bottom of the door jambs are wet, as does the bottom of door at hinge side.

Is it wet?

darrenheaphy

Thanks for the reply Not it's neither wet nor damp to the touch. That black staining in the grout between the tiles was there when we bought the house so I guess it's possible that the grey staining was there also ...

Juwwi

It looks like a leak to me aswell.
Maybe take off that lenght of skirting board in the first picture and have a look.

Outkast_IRE

If its underfloor heating is there a pressure guage somewhere on the system ? do you need to top us the system often?

darrenheaphy

Good point, I never thought of that. There is a decent pressure on the valves and doesn't need top ups (or rather, I've never topped it up). It's a fairly self regulating heat pump (it's a PZP Komplet earth-water one)

Outkast_IRE

darrenheaphy wrote: »

Good point, I never thought of that. There is a decent pressure on the valves and doesn't need top ups (or rather, I've never topped it up). It's a fairly self regulating heat pump (it's a PZP Komplet earth-water one)

There should be a pressure guage somwhere on the system specifically for the heating , usually at the underfloor heating manifold or at the heatpump, if you havent had to top it up thats probably a good sign

but i would look for the guage anyway and make sure an "automatic filler hasnt been fitted" this shouldnt be used but they are around where they top up the system automatically as needed".

As was stated there should be some feeling of moisture or damp and the door jam etc if it was a leak , a moisture detector might be handy , you would often see fellas using them before laying a wooden floor down etc.

darrenheaphy

Thanks again for that. What would an automatic filler look like? There's a reserve tank for the chemical used to prevent freezing but I don't recall any additional water supply. There's the normal outgoing and incoming supply from the pump supply as it does the rounds around the house.

Outkast_IRE

darrenheaphy wrote: »

Thanks again for that. What would an automatic filler look like? There's a reserve tank for the chemical used to prevent freezing but I don't recall any additional water supply. There's the normal outgoing and incoming supply from the pump supply as it does the rounds around the house.

This would be a point in the system where the water pressure could be topped up if necessary, as i said in many systems its with the underfloor heating manifold , the manifold is where all the heating pipes come up from underground into a Header Pipe or manifold and then this manifold is connected to the supply or return from the heatpump .

As i said i wouldnt worry too much but if you know where it is its worth a glance.

kdunderfloor

hi,i had a woman contact me with the same problem,she got a guy out with a thermal imaging camera to pin point the leak..your grout definitely looks damp and id suggest your sure that the ufh pressure hasnt dropped and auto filled up again..thermal imaging works well in this case but expensive

darrenheaphy

Is it possible that the thermostat is too high? We had it set to 26, and in some places a max 36.

We have a basement with a concrete ceiling (into which kitchen and dining room under floor pipes are buried) an I've noticed a patch there that's wet to touch. I presume if it was a proper leak it would be gradually getting larger, which it isn't but is constantly there. Could that be us having the heating set too high (only comes on during the night)?

slowburner

darrenheaphy wrote: »

Is it possible that the thermostat is too high? We had it set to 26, and in some places a max 36.

We have a basement with a concrete ceiling (into which kitchen and dining room under floor pipes are buried) an I've noticed a patch there that's wet to touch. I presume if it was a proper leak it would be gradually getting larger, which it isn't but is constantly there. Could that be us having the heating set too high (only comes on during the night)?

If it is a pinprick leak or a weep, then the quantity of water escaping into the surrounding area might be small enough to evaporate with the high heat you have set on the thermostat (26 - 36º is very high).
It is fairly likely that if the heat was turned down, the stain would spread.

slimjimmc

Higher temps usually means pipes/joints expanding ever so slightly and higher water pressure, either of which could potentially cause any leak to weep more. I would have thought having the thermostat at max shouldn't cause a problem if the system was sound.