Unvented system leak issue

[Novice needs help]

I had my old boiler replaced and changed to an unvented system and relocated into the loft. Everything worked well for the first month or so. I then had a different plumber and builder to create new bathrooms and also put on new radiators throughout. The original plumber came back to recommission the system and when he did so only one radiator got slightly warm at the bottom and at this time there was a squealing noise which he said was air in the system but it would find its way out. He then left after about an hour of being there and shortly after the noise became even worse and I went into the loft and it was coming from the pump which was also red hot, so I turned off the whole system. I told him and he said the builders plumber must have left solder in the system when he was putting the radiators on and he would sort a time to come back out and sort out. A day later (when the boiler was still off) the pressure relief valve discharged a lot of water down the side of the house.
A few weeks went by and the original plumber came back to pressure the system but at this point the boiler was losing pressure both times he tried to put pressure in. The pressure relief valve was changed as it has no resistance on it at all. Long story short one of the quick fit john guest t joints has popped and there is a leak under the downstairs floor.
Both plumbers are pointing the fingers to each other, one saying the other over pressured the system and cooked the pump which caused the joint to blow, and the other saying he didn’t fit the joint properly in the first place and the other issues (PRV) must be unrelated and just down to a faulty part??
I am in the middle and need to have the floor up to fix the leak and find out if there are any other leaks. But I want to know who is likely at fault?? Any help?

 

[exedon2]

Speedfit fittings are rated at 3 bar at 82 C
( 12 bar at 20C) as prv worked at presumably 3 bar system should have been within design limits.
I would be looking at guy who installed pipework/fittings.

 

[ShaunCorbs]

Also there would of been a pressure loss if it was leaking so this should of been noticed

 

[Novice needs help]

Thanks so much for your reply that’s very useful. The argument that the 2nd plumber ( who did the radiator fit after the new unvented system was out in) is saying that if the joint was leaking it wouldn’t have held up for his air test or the first time that the original plumber came to pressure the system. He said the only reason there is now a leak is before the other plumber over-pressured the system which then cooked the pump.

 

[Novice needs help]

Thank you very much for taking the time to reply this is a great forum. After they PRV had discharged there was 0 pressure which I assume is to be expected. But I didn’t check the pressure myself before this point so can’t tell if there was always a small leak there which has got worse with the re pressure attempts. I can’t understand why when the boiler was turned back on for the first time one of the rads started to get warm but there was a squealing noise which then developed into a horrendous grating noise from the pump? Could this be because of a leak from the start?

 

[Ben-gee]

Why are you jumping between plumbers?

If it worked fine for a month as you say (original plumber’s work presumably fine)

Then builder and 2nd plumber come and there’s a problem afterwards - it would be very unfair to blame the first plumber.

 

[Novice needs help]

I take this post completely. The difficulty is the 2nd plumber is saying it is 100% obvious that it happened due to over-pressuring. I have no idea what who should be liable

 

[Ben-gee]

Very little is 100% obvious in this line of work!

If it’s a speed fit joint, dismantle it and it should be fairly clear wether or not the pipe was pushed in far enough in the first place as there will be a visible difference between pipe that has been either side of the o-ring.

I would be more concerned with getting the problem solved than with finding who to blame. Anyway the process of solving the problem will probably also reveal what caused it.

Either get a third plumber in to solve it, and ask them to explain the cause (this should tell you who’s ‘fault’ it was)
Or pick the best/friendliest/most conscientious or the other two- if doesn’t sound like a big problem and life is short.

 

[Novice needs help]

Thanks for this. Part of the process of trying to see who would be at fault is because the new flooring that we have had laid is herringbone glued in individual strips with a sub board and feathered edges to get the whole place level. That in itself cost thousands and taking up the floor and replacing will be a costly job as it needs to be level with the rest. If the flooring wasn’t down it wouldn’t necessarily be a big issue. Also the pump will need replacing which is another expense someone will have to pay for, on top of the invoice I am being chased for for the plumber to come back and pressurise the system (even though it’s not working still). The cost of it soon starts to add up

 

[Ben-gee]

There may be a way to re-route the pipe- ie pick it up either side of that room and just leave the dodgy bit under the floor but unconnected.

How come anyone thinks it’s a dodgy joint under that particular floor if they can’t get at it to see?

Anyway this is a job to get resolved on site not over the internet. It needs doing, there will be a way, it will cost something.- that’s life.

 

[Novice needs help]

Forums like this are a great source of expertise (like yours) so I do think investigating on the internet worthwhile. I know there is a leak under that piece of flooring as you can hear it pouring form the air Brick. It’s not a small leak it was a big enough leak to drop the whole pressure within 10 minutes. Yes paying for things is part of life but the question is who pays, because it won’t be me

 

[exedon2]

Was the first fix pressure tested?
Speedfit recommend testing at 2 bar for 10 minutes then up the pressure to 10 bar for a further 10 minutes,.
We always pressure test first fix even on small extention jobs.

 

[Novice needs help]

The plumber said he did an air pressure test for an hour and it held with no leaks, that’s why he gave the green light for the floor to go down. His argument is that if there was a leak it would have showed up straight away rather than happening on the 4th time of pressuring

 

[ShaunCorbs]

And his proof he tested ?

 

[Novice needs help]

Just his word and the builder who said he saw him do it too, no other proof though

 

[exedon2]

Manufacturers instructions ask for a hydraulic wet test.

 

[Novice needs help]

Brilliant, thanks for that info, will be very useful as I must admit I did think it should have been filled and tested raster than air