1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Noisy Glow Worm

Discussion in 'Plumbing and Central Heating' started by Dr Spock, 17 Oct 2007.

  1. Dr Spock

    Dr Spock

    Joined:
    17 Oct 2007
    Messages:
    4
    Thanks Received:
    0
    Country:
    United Kingdom
    Hi

    I have a GW 18hxi, installed in a conventional open system in my 3 bedroom house. The boiler is in what used to be the garage, with the flue going vertical through the flat roof, with termination kit. It's been fitted about a year.

    The boiler emits what can only be described as a howl from the flue on initial fire-up from cold, lasting a few seconds. It can be heard all over the house, and even 2 doors down the road ! Once running, all seems OK.

    The engineer thought it might be high gas pressure, and he has checked that, but it's nigh-on the 8" WG recommended. He's now at a bit of a loss.

    The flue is well fixed, and I've even tried to hold it when it starts up, as I thought it might be a resonance of some sort. Didn't make any difference.

    Has anybody had a similar experience ?
     
  2. Sponsored Links
  3. EliteHeat

    EliteHeat

    Joined:
    28 Jan 2006
    Messages:
    1,094
    Thanks Received:
    3
    Location:
    London
    Country:
    United Kingdom
    Wouldn't a howling noise point to the fan?
     
  4. Dr Spock

    Dr Spock

    Joined:
    17 Oct 2007
    Messages:
    4
    Thanks Received:
    0
    Country:
    United Kingdom
    Yes. it sounds like an air movement problem. Could the fan be coming on too fast or too soon, before the combustion is properly underway ? What could cause this ?
     
  5. gas4you

    gas4you

    Joined:
    23 Feb 2007
    Messages:
    21,178
    Thanks Received:
    1,912
    Location:
    Norfolk
    Country:
    United Kingdom
    I assume Elite meant the fan bearings :confused:
     
  6. Rob

    Rob

    Joined:
    14 Aug 2006
    Messages:
    5,556
    Thanks Received:
    707
    Location:
    London
    Country:
    United Kingdom
    Incorrect mixture?
     
  7. Sponsored Links
  8. Dr Spock

    Dr Spock

    Joined:
    17 Oct 2007
    Messages:
    4
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks for the suggestions. It doesn't sound like bearings, and why would the noise disappear after a few seconds ?

    The mixture settings I assume are factory set. There's no mention of any adjustment in the Installation info.
     
  9. gas4you

    gas4you

    Joined:
    23 Feb 2007
    Messages:
    21,178
    Thanks Received:
    1,912
    Location:
    Norfolk
    Country:
    United Kingdom
    As this is a discontinued Vaillant Ecomax Pro there should be an adjustment to set the gas mixture (co2) content.
     
  10. Agile

    Agile

    Joined:
    26 Jun 2004
    Messages:
    64,020
    Thanks Received:
    4,591
    Location:
    London
    Country:
    United Kingdom
    You may assume things but part of the commissioning process is to check the CO² percentage with a flue gas analyser.

    Did the CORGI installer complete the Benchmark Certificate or was it a cowboy installation?

    Tony
     
  11. Dr Spock

    Dr Spock

    Joined:
    17 Oct 2007
    Messages:
    4
    Thanks Received:
    0
    Country:
    United Kingdom
    You were correct about probably being to do with the mixture. I sent the GW Tech Dept an email, and received the following response:

    " The problem you have is fairly common with these type of appliances. I
    think you have an issue with your gas/air mixture which is slightly out,
    resulting in a noise on firing.

    It is very easy to rectify. The engineer needs to get his flue gas
    analyzer on the appliance and carry out a check on the CO2 % level while
    the appliance is locked at both a high and low rate of ignition. This is
    all specified in the installation manual in the servicing section.

    Reasons for this problem other that the mixture being slightly out could
    be low inlet gas pressure to the appliance, or a restriction on the air
    inlet side of the flue, but in most cases, once the engineer has
    analyzed the products, and made adjustments on the gas valve as
    necessary, the noise will go away. "

    Full marks to GW for a prompt and reasoned response, and thanks to you guys for your comments and pointers.
     
  12. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Loading...

Share This Page