Water pressure loss - ideal logic combi1 35

jarvis92

Hi,

I live in a new house, only 3 years old. The boiler was installed when the new house was built. I serviced it every year other than this year due to COVID. On April this year, the boiler started loosing water pressure. I checked around all the heaters, and nothing was leaking anywhere. I had to top up every 5-7 days. I called a plumber out, he said it’s a very small leak, hence why it’s taking so long. He put a sealant in, and that fixed the issue. 

2 weeks ago, I had to top up again and this stayed steady for about 12 days. I can see that the pressure is going down slowly yet again, I assume I will have to top up by the end of this week. 

What should I do? Get the plumber out and ask him to use another sealant? Not sure what to do. I hear topping up every time can be bad too. 

Any advise would be appreciated.

neilmcl

If there's really a leak then you need to find where it is. Just chucking radiator sealant into the system, which I assume is what your plumber did, isn't going to fix the issue over the long term. What are you topping it up to and what is it now?

jarvis92

The plumber inspected around the house last time, and he said there was a small leak somewhere. I assume there is a leak - that would explain why the sealant worked earlier on in the year. I have looked around the house today again, radiators, ceilings, copper valve outside, but I cannot find any sort of leak.

I topped it up on Wednesday (28/10) to just above 1 bar. Currently, it’s sat just above 0.8 bar. I would say I will need to top up before the end of this week.

Is there some sort of way to find out if there is a leak in the pipes, or it’s an issue with the boiler? I read a few articles where people have removed the flooring to find the leak, but still not got it working. I am dreading that. 

Jeepers_Creepers

Hi Jarvis.

Your boiler will almost certainly have a 15mm copper pipe coming out from under it which heads out through an external wall. On the outside, it'll either be pointing down close to the ground, or else be curved back on itself and facing the wall. This is the safety discharge pipe - can you locate it?

If all is well, there should be nothing coming out that pipe. Touch the end with your finger to see if there's any wetness - is there? If in any doubt, get a small clear plastic bag and loosely tape/rubber-band it around the end so it'll catch any water that does come out.

If the leak is within the boiler, then that's the most likely way it exits your system, and this would be good news as it's easily sortable. 

The other way water can leave your boiler is via the plastic condensate pipe - you should be able to locate this too. It'll be trickier to determine if the leak is coming out here as 'water' is released from this at regular intervals in any case. Really, the the only way would be to pressurise your boiler and then leave it off for a week - see if anything comes out there when it's not actually working...! With modern boilers, this would be an unlikely source anyway, as they've kind of sorted the early 'high efficiency' boiler issues of corroding main exchangers. So I doubt it's via this anyway.

Failing that, it's sadly a case of 'hunt the leak'. Does your house have a foundation void under the floor? Can anyone get in there to check the pipes? I have heard of other ways of tracing leaks - but not sure how - so you could try a G-search for this. 

Jeepers_Creepers

Hang on - 3 year old house? Doesn't it have a warranty? Would it cover this? Surely it's an inherent fault? 

jarvis92

Jeepers_Creepers said:

Hi Jarvis.

Your boiler will almost certainly have a 15mm copper pipe coming out from under it which heads out through an external wall. On the outside, it'll either be pointing down close to the ground, or else be curved back on itself and facing the wall. This is the safety discharge pipe - can you locate it?

If all is well, there should be nothing coming out that pipe. Touch the end with your finger to see if there's any wetness - is there? If in any doubt, get a small clear plastic bag and loosely tape/rubber-band it around the end so it'll catch any water that does come out.

If the leak is within the boiler, then that's the most likely way it exits your system, and this would be good news as it's easily sortable. 

The other way water can leave your boiler is via the plastic condensate pipe - you should be able to locate this too. It'll be trickier to determine if the leak is coming out here as 'water' is released from this at regular intervals in any case. Really, the the only way would be to pressurise your boiler and then leave it off for a week - see if anything comes out there when it's not actually working...! With modern boilers, this would be an unlikely source anyway, as they've kind of sorted the early 'high efficiency' boiler issues of corroding main exchangers. So I doubt it's via this anyway.

Failing that, it's sadly a case of 'hunt the leak'. Does your house have a foundation void under the floor? Can anyone get in there to check the pipes? I have heard of other ways of tracing leaks - but not sure how - so you could try a G-search for this. 

Hi Jeepers,

thank you for your response. I have located the pipe and checked it earlier on today. There is nothing on the pipe, or on the floor near it. I poked my finger inside the pipe and it’s dry, I got some dust on my fingers that’s about it. 

A plastic condensate pipe - is that what it’s called? Where about would this be? 

There is no foundation void under the floor, I would have to rip into the flooring which is what i am worried on. A G-search? Is that a service a company would provide? 

Thanks.

jarvis92

Jeepers_Creepers said:

Hang on - 3 year old house? Doesn't it have a warranty? Would it cover this? Surely it's an inherent fault? 

I have a building warranty for 10 years. But the boiler warranty ran out last year. It was only for 2 years sadly. I thought as it’s a new house, everything would be fine. So I didn’t renew the warranty further, as it needed a premium. 

daveyjp

Go round each radiator and check the valves are tight. It only needs one not to be nipped up fully for pressure to escape.

jarvis92

daveyjp said:

Go round each radiator and check the valves are tight. It only needs one not to be nipped up fully for pressure to escape.

Thank you - I will check around the house and tighten the valves. But, that doesn’t explain why the sealant fixed this issue in the first place  

Jeepers_Creepers

jarvis92 said:

Jeepers_Creepers said:

Hi Jarvis.

Your boiler will almost certainly have a 15mm copper pipe coming out from under it which heads out through an external wall. On the outside, it'll either be pointing down close to the ground, or else be curved back on itself and facing the wall. This is the safety discharge pipe - can you locate it?

If all is well, there should be nothing coming out that pipe. Touch the end with your finger to see if there's any wetness - is there? If in any doubt, get a small clear plastic bag and loosely tape/rubber-band it around the end so it'll catch any water that does come out.

If the leak is within the boiler, then that's the most likely way it exits your system, and this would be good news as it's easily sortable. 

The other way water can leave your boiler is via the plastic condensate pipe - you should be able to locate this too. It'll be trickier to determine if the leak is coming out here as 'water' is released from this at regular intervals in any case. Really, the the only way would be to pressurise your boiler and then leave it off for a week - see if anything comes out there when it's not actually working...! With modern boilers, this would be an unlikely source anyway, as they've kind of sorted the early 'high efficiency' boiler issues of corroding main exchangers. So I doubt it's via this anyway.

Failing that, it's sadly a case of 'hunt the leak'. Does your house have a foundation void under the floor? Can anyone get in there to check the pipes? I have heard of other ways of tracing leaks - but not sure how - so you could try a G-search for this. 

Hi Jeepers,

thank you for your response. I have located the pipe and checked it earlier on today. There is nothing on the pipe, or on the floor near it. I poked my finger inside the pipe and it’s dry, I got some dust on my fingers that’s about it. 

A plastic condensate pipe - is that what it’s called? Where about would this be? 

There is no foundation void under the floor, I would have to rip into the flooring which is what i am worried on. A G-search? Is that a service a company would provide? 

Thanks.

Cool - the dry and dusty pipe is pretty conclusive! 

The condensate pipe should also be obvious as it'll be the only 22mm plastic one coming from under the boiler. It'll either head out through the house wall and end up in a drain, or it could be connected to a waste drain inside the house. 

It would be unusual for a 3-year old boiler to leak 'system' water (which is the boiler/radiator water sealed under pressure in your system) this way, tho', as it would only occur if the main exchanger had suffered a crack or corrosion - rare these days. (Some early HE boilers had aluminium or copper exchangers in them and these unsurprisingly corroded with the acidic condensate!)

The only other way for the boiler to leak would be visibly from underneath. 

It's hard to judge just how much water is concerned here, but I'd very roughly estimate that a drop of pressure of 0.3 bar (your last figure) would require something like a cupful? When you re-top the pressure, you'll have an idea by the sound of the flow for however many seconds it takes. So we are not talking about a 'flood', but we are certainly talking about an amount that will be noticeable when found... For pipes buried in concrete floors, I'd expect a damp patch to reveal themselves, especially as the system has been topped up repeatedly. But of course this would require the floor coverings to be lifted first.

Sorry - by G-search I mean 'Google'! I've heard of companies that can use - I dunno - infra-red imaging? to try and locate leaks? Perhaps by detecting the 'warm patch'.

Your boiler warranty might only have been for 2 years, but surely your 'system' - the rads and pipes - have more than this? Isn't there an NHBC warranty or similar? Should it turn out that the fault is with the boiler, I would suggest that this is most definitely still protected too; a modern boiler should not - would not - fail in 3 years unless it had an inherent fault.

Jeepers_Creepers

Make and model of boiler?