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Discuss Combi boiler flow temperature with underfloor heating in the Underfloor Heating Forum area at

  1. Matchless.plumb

    Matchless.plumb Trusted Plumber GSR

    England is 20 years behind mate to start with.
    As I said if you set 55 the return will be about 10kelvin different so it will use the flue gas as energy instead of wasting.

    Boiler plus is for 20 years in Germany .. we only install boilers with integrated heat recovery units , weather compensation sensors etc. However, Like Atag says, they are apparently Europe’s best boiler which is wrong market leader is and will be Vaillant .. the guy from Atag is a kitchen company by the way he just started 10 years ago to do some boilers .. :) Lol
    • Disagree Disagree x 1
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    If sized correctly I would want more of a difference more like 15-20dc
  3. Matchless.plumb

    Matchless.plumb Trusted Plumber GSR

    As said in my previous post ideally you want 15dc ( that’s the ideal figure ) between flow and return. But it’s totally silly to run the flow temperature via 70dc . the lower it is the more efficient it runs. And due to the passive heat recovery units and weather compensation you will gain even more on savings. But if you think you are right that’s good with me I’ll stick to the 55dc. Why disagreement? Due to the fact I know that Atag isn’t market leader or because England is 20 years behind ?
  4. kam187

    kam187 New Member

    Erm I see you guys seem to have got into a debate over this!

    So if I only want 40-50C for the floor what do you recommend I run the boiler flow at if not 70C

    I understand you both have different views but I’d like to hear the lower temperature recommendation too.

    Why would I run it at 60 C If I only need 40-50? Id be happy to run the underfloor at 45
  5. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!


    Also running at a lower temp would alter your hot water performance eg longer time to wait for hot water etc
    • Disagree Disagree x 1
  6. kam187

    kam187 New Member

    Worchester replied and said it's fine to run it at 50C, and also it won't affect the hot water.

    I'm waiting for the TLV's and i'll do some tests both ways.
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