Leak under kitchen unit, where is it coming from?

Ganga

RoughNeck said:

Albermarle said:

RoughNeck said:

We've also had our new-ish boiler (2 years old) lose all its pressure twice within 24hrs. I wonder if that's related? This is becoming quite the headache! It might well be an insurance job, I'm not sure. I've got someone coming round this afternoon to have a look to advise further!

Could it be a heating pipe running under the kitchen units ( to/from  a radiator) that is leaking ?

I think this is definitely a possibility. The really annoying thing is that we have kitchen tiles laid on concrete . Whatever happens it looks as though there may be some digging involved. A real cowboy has put some of this house together in the past and it wouldn't surprise me in the slightest if it's due to something they neglected to do properly. I just saw a video on YouTube about a plumber locating a leak in the pipework that was causing a boiler to lose its pressure. So it could be something similar. Granted, we've had this leak/damp for a couple of weeks now and only in the last 24hrs has the boiler lost the pressure twice.

Unless the small hidden leak has become a large hidden leak ,hopefully the person you get out to investigate will put it right.

JohnB47

You say you've checked under the sinks but have you checked all of the waste pipe joints under there? It's fairly typical for installers to be sloppy about cutting pipework too short or long and the joints are distorted and leak - possibly only when warm/hot water is put through them. 

What about the under-sink cupboard. Any water lying on the bottom of it - under the pipework?

Another possibility is the pipework is partially blocked and the rush of emptying washing machine water is not getting away quick enough and is coming up and out of a stand pipe. Ignore this if your washing machine hose is not hooked into an open stand pipe.

RoughNeck

My friend (carpenter come jack of all trades kind of chap) did exactly what is suggested above - looking at the joins. There wasn't anything obvious and no water drops/stains from the sink on the wooden unit below. However, we wrapped blue towel around each join just to see if anything came out. We checked the washing machine again just in case and then put another cycle on. I found that the blue towel was slightly wet on one of the isolation valves and maybe a drop or two where the washing outlet connects to the waste pipe too. He's going to look at replacing them today. It would be hard to believe that a small drip or leak like that could cause that amount of damp/wet underneath, but then I guess over time it could just have built up. Our boiler pressure is now dropping every hour or so, so something definitely isn't right.

Typically, I have Vaillant coming out tomorrow, but a threat of a £98 call out charge if they don't find an issue with the boiler makes me want to cancel it in case the new isolation valves sort the issue. Perhaps it makes more sense to delay the Vaillant visit...

RoughNeck

Thank you for everyone's advice too!

ThisIsWeird

RoughNeck said:

My friend (carpenter come jack of all trades kind of chap) did exactly what is suggested above - looking at the joins. There wasn't anything obvious and no water drops/stains from the sink on the wooden unit below. However, we wrapped blue towel around each join just to see if anything came out. We checked the washing machine again just in case and then put another cycle on. I found that the blue towel was slightly wet on one of the isolation valves and maybe a drop or two where the washing outlet connects to the waste pipe too. He's going to look at replacing them today. It would be hard to believe that a small drip or leak like that could cause that amount of damp/wet underneath, but then I guess over time it could just have built up. Our boiler pressure is now dropping every hour or so, so something definitely isn't right.

Typically, I have Vaillant coming out tomorrow, but a threat of a £98 call out charge if they don't find an issue with the boiler makes me want to cancel it in case the new isolation valves sort the issue. Perhaps it makes more sense to delay the Vaillant visit...

If your boiler is losing pressure that rapidly, then it needs sorting regardless of whether it's the cause of this wet patch. And, the boiler system is completely independent of the W/M valves, so replacing the dripping WM valve won't fix the boiler.
There is a way of testing whether the boiler loss is coming from within the boiler, and that's by repressurising it, turning it off, and isolating it from underneath using the valves on the CH Flow and Return pipes. If the pressure still drops, the leak is from within the boiler. If the pressure drops only when you reopen the valves, then it's from your rads and pipework.

Albermarle

ThisIsWeird said:

RoughNeck said:

My friend (carpenter come jack of all trades kind of chap) did exactly what is suggested above - looking at the joins. There wasn't anything obvious and no water drops/stains from the sink on the wooden unit below. However, we wrapped blue towel around each join just to see if anything came out. We checked the washing machine again just in case and then put another cycle on. I found that the blue towel was slightly wet on one of the isolation valves and maybe a drop or two where the washing outlet connects to the waste pipe too. He's going to look at replacing them today. It would be hard to believe that a small drip or leak like that could cause that amount of damp/wet underneath, but then I guess over time it could just have built up. Our boiler pressure is now dropping every hour or so, so something definitely isn't right.

Typically, I have Vaillant coming out tomorrow, but a threat of a £98 call out charge if they don't find an issue with the boiler makes me want to cancel it in case the new isolation valves sort the issue. Perhaps it makes more sense to delay the Vaillant visit...

If your boiler is losing pressure that rapidly, then it needs sorting regardless of whether it's the cause of this wet patch. And, the boiler system is completely independent of the W/M valves, so replacing the dripping WM valve won't fix the boiler.
There is a way of testing whether the boiler loss is coming from within the boiler, and that's by repressurising it, turning it off, and isolating it from underneath using the valves on the CH Flow and Return pipes. If the pressure still drops, the leak is from within the boiler. If the pressure drops only when you reopen the valves, then it's from your rads and pipework.

Just out of interest, I checked my set up and no sign of said valves. Is that not normal? Presumably if I had a pressure loss it would make it more difficult to locate what was happening.

ThisIsWeird

Albermarle said:

ThisIsWeird said:

If your boiler is losing pressure that rapidly, then it needs sorting regardless of whether it's the cause of this wet patch. And, the boiler system is completely independent of the W/M valves, so replacing the dripping WM valve won't fix the boiler.
There is a way of testing whether the boiler loss is coming from within the boiler, and that's by repressurising it, turning it off, and isolating it from underneath using the valves on the CH Flow and Return pipes. If the pressure still drops, the leak is from within the boiler. If the pressure drops only when you reopen the valves, then it's from your rads and pipework.

Just out of interest, I checked my set up and no sign of said valves. Is that not normal? Presumably if I had a pressure loss it would make it more difficult to locate what was happening.

Make and model of your boiler, Albermarle?

I'd be very surprised if it didn't have these valves. They might not be obvious - some are operated using a screwdriver. Others have actual levers fitted.

For a system that's losing pressure, it's one of the best checks to make to try and see if it's from within the boiler, or external to it - pipes and rads (after the very first checks of the safety discharge and condensate pipes). It's important that the boiler is turned off when the valves are closed, as it obviously won't be able to operate correctly with these shut.

GDB2222

With the boiler turned off, do you still get a pressure drop?

Albermarle

ThisIsWeird said:

Albermarle said:

ThisIsWeird said:

If your boiler is losing pressure that rapidly, then it needs sorting regardless of whether it's the cause of this wet patch. And, the boiler system is completely independent of the W/M valves, so replacing the dripping WM valve won't fix the boiler.
There is a way of testing whether the boiler loss is coming from within the boiler, and that's by repressurising it, turning it off, and isolating it from underneath using the valves on the CH Flow and Return pipes. If the pressure still drops, the leak is from within the boiler. If the pressure drops only when you reopen the valves, then it's from your rads and pipework.

Just out of interest, I checked my set up and no sign of said valves. Is that not normal? Presumably if I had a pressure loss it would make it more difficult to locate what was happening.

Make and model of your boiler, Albermarle?

I'd be very surprised if it didn't have these valves. They might not be obvious - some are operated using a screwdriver. Others have actual levers fitted.

For a system that's losing pressure, it's one of the best checks to make to try and see if it's from within the boiler, or external to it - pipes and rads (after the very first checks of the safety discharge and condensate pipes). It's important that the boiler is turned off when the valves are closed, as it obviously won't be able to operate correctly with these shut.

It is a WB Greenstar 18Ri system boiler, about 7 years old.
Is the boiler make that relevant? I would have thought it was more how the pipework was installed?

Anyway had another look . On the flow side there is what looks like a valve each side of the pump. The sort that would need a spanner or wrench to turn. But nothing on the return pipe.

It is not important as I have no problems, but if I ever do I will be back with photos etc .

RoughNeck

The pressure is still dropping despite the replacement of isolation valves. At least that's one thing ruled out for now. I have Vaillant (or an outsourced engineer) attending tomorrow now to take a look. I just don't want them to pin anything on the fact there might be a leak under the sink area which is causing the issue with the boiler. The pressure gauge is digital, so turning the boiler off doesn't tell me much - unless I'm supposed to turn it off for a while and check again? Would this tell me that there's a leak in the pipework and it's not a boiler issue?

We have a Vaillant ecoTEC Plus 832. I'll admit I'm not familiar with isolating the flow and return pipes - any videos that anyone can point me to?

Thanks again all.