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gas pressure too low? new potterton boiler

Discussion in 'Plumbing and Central Heating' started by cjm123, 26 Oct 2011.

  1. cjm123

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    Hi

    I live in a 3rd storey flat in London. I had a boiler installed recently, a Potterton Gold HE A condensing combi.

    The boiler has become very very noisy on startup - the case vibrates and gives a rumbling sound. The installer came back to check it and thought perhaps that there was a fault with the gas valve, so he called Heat Team who came out as the boiler is in warranty.

    The engineer just left and his diagnosis is that my pressure is too low. He measured it and as the boiler fires up the pressure drops from 18 down to 8. He said the vibrating is occurring because the boiler isn't getting enough gas. He stated that I would have to replace all of the pipes into the property. The current pipes are 22mm, and the gas box is on the ground floor, so they climb 4 floors before entering the property.

    I don't know much about this, so I just want to check, is this a plausible scenario? I only ask because the old boiler did not have this issue (it leaked and was scaled up, but didn't have this problem), and also because I got several quotes for installations (including BG), and none of them talked about replacing these pipes. I remember one chap checking the pressure and saying it would be ok.

    I just want to make sure because replacing all of these pipes sounds like a huge job. What size pipe would I need then? And, would it involve getting under the floors to replace those pipes too or would the ones on the outside of the building cover it?

    Thanks for your time.
     
  2. cjm123

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    ...incidentally my neighbour had a boiler fitted recently and the installers upgraded the 22mm to 28mm until it gets to our level, where it reverts back to 22mm...
     
  3. mickyg

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    if its dropping to 8mb then the pipework is either undersized or restricted in some way. It shouldn't drop by more than 1mbar at the appliance inlet or aprx 2-3mbar at the gas valve on some modern boilers. Your installer should check the appliance inlet pressure and gas rate after installation, it doesnt sound like he has done this else he would have noticed the problem when he'd finished.
     
  4. Rob

    Rob

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    8 is extremely low. Id imagine the guvenor is faulty.
     
  5. Agile

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    You seem to have had a nupty installer who did not consider the gas supply before installation, did not commission the boiler or complete the Benchmark and is probably not Gas Registered! At least not for long!

    Surely the neighbour's upgraded gas pipe should have given you a clue?

    Tell us about your nupty installer! Is he gas registered? If not do you know who he really is? If so then report him to Gas Safe and have their inspector come and investigate. This is really a very serious thing for him to have done ( or rather not done ).

    The warrantee engineer should have checked the pressure at the gas valve with the boiler running. Did he do that???

    Tony
     
  6. cjm123

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    What is the guvenor, is it in the boiler or in the meter/pipes? I'm just interested in whether you are saying that you think the boiler itself has a problem or if you think the existing pipes (22mm) and the 4 storey climb is the cause.

    If so I will start getting quotes to get these pipes changed. I'd just hate to change them and have it not solve the problem.
     
  7. gaswizzard

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    The heat team guy is correct , had a WB 40 cdi sound like a freight train when customer was using range cooker , working pressure on this boiler was 15mb min/12mb max , CO2% was wayyyyyyyy out , gas supply upgraded & all is good.
     
  8. Agile

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    It seems my posting above is invisible!

    The governor is something at the meter that sets the pressure to 21 mB on load.

    As you seem very content to pay a lot more to have the gas pipes upgraded I can only assume that you had a cheap boiler installation and knew they were not gas registered ???

    To see what upgrading is required it needs proper measurements of the gas pressures at the meter and at the boiler. It still MIGHT just be a fault at the meter!

    Tony Glazier
     
  9. mickyg

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    so what about the installer???
     
  10. Rob

    Rob

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    I see undersized supplies every day and while 3 storeys high and only in 22mm is probably undersized, to only get 8mb seems unusually low.

    Plus the OP says it has only just started happening.

    Did the Heatteam man check the meter at all?

    If not give 0800 111 999 a call and ask for their opinion. No point going back to the installer at this stage.
     
  11. expertgasman

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    Plus the OP says it has only just started happening.

    Did the Heatteam man check the meter at all?

    If not give 0800 111 999 a call and ask for their opinion. No point going back to the installer at this stage.[/quote]

    OP: When was the boiler fitted?
     
  12. cjm123

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    Thanks everyone for your replies.

    Tony - I wasn't ignoring your first comment, I didn't see it until now. Looking at the time I think we probably both posted at the same time. Incidentally you and I have talked about this installation previously, it was a few months ago.

    The neighbour had his work done very recently (more recently than me) so his pipework hadn't been done at that point.

    Tony/Rob - yes, the Heat Team guy did check the pressure at the meter while I ran the boiler. He was happy with it and thus diagnosed the pipes as being the issue (having already checked the pressure at the boiler first)

    expertgasman - it's been about 5 months since the boiler was installed now. Sorry, I've obviously been unclear about how long the noise has been going on for, it hasn't only just started. It didn't start immediately but within the first week or two certainly. I think it's got a little worse over time. It's taken me a long time to even get the Heat Team engineer out for various reasons. I've been away a lot, working abroad etc. Then it's taken me quite a while to actually get them to come - they cancelled on me twice, i had to rearrange it myself once, etc, etc. It's all taken a lot longer that it should have.
     
  13. expertgasman

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    Was the benchmark completed, and does it state the measured gas pressure?

    Why haven't you contacted the installer - OR WAS THAT TONY?

    if you are the 4th storery (Ground plus 3), and you can't see the route for the gas, then there may be a lot of restrictive bends and elbows. It will be undersized, and the route may exacerbate the problem. I try not to criticise work I can't see, but this was probably predictable.
     
  14. cjm123

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    I'm not sure if that's a joke or not but just to be absolutely clear, no, Tony didn't have anything to do with this installation at all. He was just kind enough to discuss it with me after the fact, when I had come across him on this forum.


    No, the benchmark was not completed. I did contact the installer about the noise problem, he came back to look at it and his opinion was that there was probably a fault with the gas valve. Hence we called Heat Team who have made a different diagnosis.


    Re the pipe work - i can see it, and yes, there are 4 right angle bends on it's way upwards, avoiding various protrusions. And yes, it is ground plus 3. It sounds like many of you would have expected this to be an issue.

    I only wanted to check this because as i said, i got a few quotes done, and none of them mentioned that this might need doing, the BG guy measured the pressure at the boiler and thought it would be fine. But it sounds like several guys here are pretty sure that the pipes are the issue, which is enough to confirm that Heat Team guy's diagnosis, as far as i am concerned.
     
  15. Dan_Robinson

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    Schoolboy error on your Installers' part (being nice that is).

    Get a competent person to install a gas supply, but consider giving Gas Safe a ring first.
     

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