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Discuss Steam from condensate drain in the Central Heating Forum area at

  1. Mr Fog

    Mr Fog New Member

    I am having my kitchen revamped and have removed the sink and waste pipes.

    However the condensate drain pipe was connected to the waste pipe so I therfore temporarily dropped the condensate drain into a bucket.

    I have since turned on the boiler so my wife could take a shower and noticed water vapour/steam coming from the condensate drain pipe...

    Is this normal or a problem with the boiler which is an Isar Ideal HE24.

    Many thanks in advance for any repies.

    Mr Fog
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Don't run the boiler into a bucket with the isar series the condense isn't trapped so needs a trap inline, normally just below the boiler / under the kitchen worktop

    It's basically what's going out the flue in the condense pipe so it's products of combustion

    Best option is enlist the services of a gas safe engy to put the condense right and maybe service the boiler
  3. Chuck

    Chuck Active Member

    Yes, it's a problem. If this "vapour/steam" is being emitted into your house so, probably, is flue gas. Turn off the boiler and get a Gas Safe engineer to come and sort it out for you.

    Broadly speaking, a condensate drain needs to be treated with as much respect as the flue. Don't mess with it or you may end up with a dead family.
    Last edited: Aug 7, 2017
  4. Mr Fog

    Mr Fog New Member

    Thank you for the replies chaps, I'll get it looked at.
  5. heliotrope

    heliotrope Plumber GSR

    So are you saying the Isar does not have an S Trap fitted?
  6. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Nope straight from the combustion chamber
  7. Chuck

    Chuck Active Member

    Last edited: Aug 7, 2017
  8. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    If there's an internal trap why is an external to the boiler trap required

    It's prob just in case the condense line gets blocked, like on the solos

  9. Chuck

    Chuck Active Member

    You seem to have found another version of the ISAR HE 24 than I did. The manual I cited is dated Aug 2009 and does not show an external trap. Anyway, the symptoms certainly suggest no trap (likely) or an empty trap (less likely) and either way I hope we can agree that the OP should stop using the boiler until the condensate drain has been reviewed and reconnected properly by a GSR.

    [I've edited my original comment appropriately.]
    Last edited: Aug 7, 2017
  10. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    2008 mine so one year apart

    And tbh think there's no trap

    As on hot water the trap should of filled / stopped steaming / venting poc to the room within 10-15 mins
    • Agree Agree x 1
  11. king of pipes

    king of pipes Trusted Plumber GSR

    Thats a bit of a no no Mr Fog products of combustion with be escaping into your kitchen get it reconnected temporarily until your revamp
    • Agree Agree x 1
  12. Mr Fog

    Mr Fog New Member

    Thanks for all your replies folks, I appreciate your help.
    Mr Fog
  13. Gasmk1

    Gasmk1 GSR

    Before mounting the boiler on the wall, the condensate drain (provided in the h/ware pack) must be connected from the boiler ā€˜Sā€™ trap to a drainage point, preferably within the building.

    Ensure that the condensate trap is full of water before commissioning the boiler . Refer to Frame 26.

    from the instructions it hought all isars had this difficult to remove and prone to blocking s trap fitted
  14. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Is that from the 2008 / earlier instructions??
  15. Gasmk1

    Gasmk1 GSR

    march 08
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