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

Is a unvented cylinder more eco than combi.

Discussion in 'Plumbing and Central Heating' started by mrbg07546, 8 Sep 2017.

  1. mrbg07546

    mrbg07546

    Joined:
    8 Sep 2012
    Messages:
    823
    Thanks Received:
    7
    Location:
    West Midlands
    Country:
    United Kingdom
    We have a unvented cylinder and was wondering if it's more eco than a combi?
     
  2. Sponsored Links
  3. Dan Robinson

    Dan Robinson

    Joined:
    1 Jul 2007
    Messages:
    56,042
    Thanks Received:
    9,424
    Location:
    Hertfordshire & London
    Country:
    United Kingdom
    Still can't find my piece of string.

    Have you tried asking your installer? ;) :LOL:
     
    • Like Like x 1
  4. mrbg07546

    mrbg07546

    Joined:
    8 Sep 2012
    Messages:
    823
    Thanks Received:
    7
    Location:
    West Midlands
    Country:
    United Kingdom
    What's the issue? It's resolved? It's a A+++ boiler and the controls (vsmart are working) to the nearest 0.1 tempreture. The weather compensation is awesome. I've linked it to my alarm via IFTT so it turns off when I leave the house. I've also set it that when I return home give a 30 minute hot water boost.


    Back to the question. I wanted to know if my bills would be less than a combi
     
  5. Dan Robinson

    Dan Robinson

    Joined:
    1 Jul 2007
    Messages:
    56,042
    Thanks Received:
    9,424
    Location:
    Hertfordshire & London
    Country:
    United Kingdom
    How the hell can we know that? :rolleyes:
     
  6. bernardgreen

    bernardgreen

    Joined:
    3 Nov 2006
    Messages:
    24,062
    Thanks Received:
    2,337
    Location:
    Bedfordshire
    Country:
    United Kingdom
    The technical department of a boiler manufacturer was asked this question on the 29th August, they have yet to reply.
    ~~~~~~~~~~~~~~~~~~
    How was actual effficiency of the [your combi] measured ? The large mass of aluminium heat exchanger has to be heated before any heat energy reaches the water. If the test was for example how much gas was required to raise the temperature of 100 litres of water 40 degs Celcius then two very different results are obtained.
    1) the 100 litres are drawn off in one continuous stream. ( heat exchanger heated only once )
    2) the 100 litres are drawn off in 20 separate 5 litre flows. ( the heat exchanger cools down while no water is flowing and then has to be reheated )
    Which method was used for the test and measurement of efficiency for [your boiler]
    Method 1) would give results that the manufacturer would like to see but method 2 is more typical of the operation of a combi gas boiler in a domestic situation.
    ~~~~~~~~~~~~~~~~~~

    Which ( combi or hot water cylinder ) is more efficient does depend on the way you use hot water. The quoted "efficiency" is not the same as performance. A boiler with a high "efficiency" calculated from laboratory test results may perform poorly in a real life installation.

    Quite possibly the answer is yes depending on how you draw hot water from the system.
     
  7. muggles

    muggles

    Joined:
    28 Oct 2005
    Messages:
    12,366
    Thanks Received:
    2,697
    Location:
    Daventry
    Country:
    United Kingdom
    Impossible to say, there are too many variables. The only way to get an accurate answer would be to install a combi in your house and compare bills before and after
     
    • Like Like x 1
  8. 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

     
  9. Sponsored Links
Loading...

Share This Page