New boiler keeps losing pressure

[kashcheema]

Hi folks,

I assume this has been asked many a times, so I do apologise in advance. My boiler which is only 6 months old started to lose pressure in March. My plumber applied 2 bottles of Fernox F4 express sealer and it seemed to fix it. It has again started to lose pressure, not drastically, maybe 0.20 bar in 24 hours. I have applied 2 more bottles to the F4 express, I'm sure however a plumber would have done a better job with it. I'm not a DIY person by any stretch of the imagination. I then turned the heating on for 1 hour at approx. 22 degrees celsius to allow it to circulate. I then let it cool down and stuck the heating on again for 1 hours at approx. 15 degrees. It is still dropping every day by about 0.05-0.10 bar a night. There is def. a leak somewhere as I had the boiler checked over by Ideal and they said there was no fault with the boiler. I have recently extended and have laid down marble flooring all downstairs and the new pipework is running under the floor and there is no chance that I want to rip any of it out. I read somewhere but i can't find the page now, that it was possible to install a device which constantly kept the pressure at say 1.5 bar without the need to repressurise every few days. Does anyone know of this and would you recommend? Alternatively, other than ripping out the floor, what other options do I have?

Thanks,

Kash

 

[steadyon]

1. Losing 0.1 bar a day is too much. Having to adjust the pressure every 6 months is acceptable.
2. Whenever you replenish the pressure your are letting fresh water into the system. This water contains dissolved oxygen which will eventually cause steel components (radiators) to rust from the inside out. So even if the "constant pressure" device exists (e.g. a pressure reducing valve set to 1.5 bar) using it is just disguising the symptoms and will damage your system over time.
3. I would suggest:
3a. Re-pressurise the system to 1.5 bar.
3b. Isolate the boiler flow and return pipes at their valves under the boiler.
3c. Do not run the boiler for a period of 24 hours.
3d. If the pressure still drops then the fault is within the boiler.
3e. Open the valves, and wait a further 24 hours. If the pressure then drops, the fault is within the system.
4. If the fault is in the boiler, get a decent engineer to fix it.
5. If the fault is in the system, then considering your floors I'd suggest a leak detection specialist to determine where the leak is.
6. Note re. isolating the boiler (3b. above). The valves used are often poor quality and may leak when operated. They would then need to be replaced, and are often ridiculously expensive for what they are.

 

[kashcheema]

1. Losing 0.1 bar a day is too much. Having to adjust the pressure every 6 months is acceptable.
2. Whenever you replenish the pressure your are letting fresh water into the system. This water contains dissolved oxygen which will eventually cause steel components (radiators) to rust from the inside out. So even if the "constant pressure" device exists (e.g. a pressure reducing valve set to 1.5 bar) using it is just disguising the symptoms and will damage your system over time.
3. I would suggest:
3a. Re-pressurise the system to 1.5 bar.
3b. Isolate the boiler flow and return pipes at their valves under the boiler.
3c. Do not run the boiler for a period of 24 hours.
3d. If the pressure still drops then the fault is within the boiler.
3e. Open the valves, and wait a further 24 hours. If the pressure then drops, the fault is within the system.
4. If the fault is in the boiler, get a decent engineer to fix it.
5. If the fault is in the system, then considering your floors I'd suggest a leak detection specialist to determine where the leak is.
6. Note re. isolating the boiler (3b. above). The valves used are often poor quality and may leak when operated. They would then need to be replaced, and are often ridiculously expensive for what they are.

Thank you for your prompt reply.

I am how the kids say these days a "noob" with all this; how would I isolate the boiler flow and return pipes at their valves? If I know how to do this, I can do the said tests. I have attached a photo of my valves in their current positions.

 

[kashcheema]

And just for my knowledge, how does a pressure reducing valve set to 1.5 bar work? Does it keep re-pressuring the system for you and maintains it at 1.5bar?

 

[SJB060685]

You say the boiler is 6 months old and started losing pressure around March time, when did you have the extension built, around March, or later?

 

[kashcheema]

You say the boiler is 6 months old and started losing pressure around March time, when did you have the extension built, around March, or later?

The boiler was added as part of the extension. The extension finished in March. Boiler installed January.

 

[SJB060685]

The boiler was added as part of the extension. The extension finished in March. Boiler installed January.

Ah I see. That doesn't sound promising. Did the installer not pressure test the pipes before the floor was laid?
Everything steadyon says above is the correct approach.

 

[kashcheema]

Ah I see. That doesn't sound promising. Did the installer not pressure test the pipes before the floor was laid?
Everything steadyon says above is the correct approach.

Floor was laid after the boiler was installed.

 

[ShaunCorbs]

Did it loose pressure/ did you notice before the floor went down ?

 

[kashcheema]

Did it loose pressure/ did you notice before the floor went down

Did it loose pressure/ did you notice before the floor went down ?

Before the floor went down it seemed fine. I suspect it’s a leak under the floor.

 

[ShaunCorbs]

Did they screw anything to the floor ?

 

[kashcheema]

Did they screw anything to the floor ?

No a latex compound was put down and then tiled over the top.

 

[ShaunCorbs]

Over a timber or concrete floor ?

 

[kashcheema]

Over a timber or concrete floor ?

New Extension floor was screed and existing area was floorboards

 

[ShaunCorbs]

If they’ve gone straight over floor boards them tiles are going to come up anyway

 

[kashcheema]

If they’ve gone straight over floor boards them tiles are going to come up anyway

Sorry I mean the floorboard area was screeded first to get level with the new screeded floor and then latex applied on both areas. Sorry long day.

 

[ShaunCorbs]

So they screwed something on top of the floorboards ?

 

[kashcheema]

So they screwed something on top of the floorboards ?

No nothing at all. Screeded and then latexed.

 

[ShaunCorbs]

That’s going to fail due to flex

 

[kashcheema]

That’s going to fail due to flex

I don’t understand Shaun, sorry what do you mean.

 

[kashcheema]

All pipe work is under the floorboards and under the screed that the builders put down when doing my extension.

 

[ShaunCorbs]

Due to movement the floor / screed will crack

 

[kashcheema]

Due to movement the floor / screed will crack

Due to movement the floor / screed will crack

But isn’t that the case with any new floor which is screeded and not put down with floorboards?

 

[king of pipes]

What Shaun is saying is that floorboards are not suitable for screeding onto these are typically fixed at 600 mm centres into a joisted floor, there is to much flex and movement in those boards to accept a screed , these boards need either fixing securely cleaning down priming and over laid with Hardi backer cement type board laid with a flexible tile adhesive and screwed at 300 mm centres before priming and fitting the floor tile , or removing and replacing with a no more ply type flooring before tiling onto . Kop

 

[exedon2]

Just to be clear is the pipework under the screed plastic? are there joints on the pipework under screed?