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Discuss piping to condensate trap to avoid freezing in the Central Heating Forum area at

  1. caroldd21

    caroldd21 New Member

    I have just had a new combi boiler fitted by an approved and Which recommended installer but I noticed that the condensate trap/soakaway was only 70 mm (should be 500 mm) from the house wall. It was not practical to link to grids which were a full house length away (poor boiler siting in my porch replacing old trad boiler) and pipe from washing machine slopes slightly uphill!

    They have agreed to put this right but they are talking about taking the pipe to the right (so we are away from the side gate and then dropping vertically to the ground where they plan to run the required 500mm horizontally to the condensate trap either just below ground level (the whole area is concreted over) or possibly a little deeper to avoid a trip hazard. They will lag the exposed pipe.

    I am a bit concerned the horizontal run just below ground will be prone to freeze. Also is it not good practice to keep joints above the ground where you can see if a leak develops (I understand the condensate is slightly acidic so you would want to know about leaks near the house).

    The only alternative I can think of is dropping the pipe at the required angle such that it arrives at the condensate trap 500 mm out from the wall though obviously it would protrude but more visible as higher up.

    I am not in any way a plumber and trying to figure this out is causing me a lot of stress. Please does anyone have any useful advice or suggestions?

    Thanks in advance
    Last edited: Dec 11, 2018
  2. Harvest Fields

    Harvest Fields S. Mod Trusted Plumber GSR Top Contributor!!

    Do you mean a soakaway?
  3. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    Is a coni pump feasible
  4. caroldd21

    caroldd21 New Member

    Thanks for replying. Sorry yes it is meant to be a soakaway. Currently it is just a 110 mm plastic container filled with limestone chipping sitting in concrete 70 mm from house. The installation instructions say it should have 100 mm of chippings around it (so total diameter of 300 mm) and be 500 mm away.

    I don't have any great objection to the soakaway if it is done properly and it works? I would guess the installer is trying to avoid installing a pump because of the extra work/expense and a lot of pipework would be needed incl getting past a side door.
  5. YorkshireDave

    YorkshireDave Plumber

    Firstly, is this a traditional heating system with rads where you have simply replaced the boiler? The reason I ask is because if it is it produces condensate at a different rate from a system designed for lower flow temps.

    If it is, then Town's suggestion of a condensate pump is spot on. It stores it till it reaches a level then pumps it all away. By pumping lots away at the same time it has more thermal mass so it's less inclined to freeze.

    Insulating only WILL NOT stop it freezing otherwise.

    The only way to ensure it does not freeze is to fit trace heating under the thinnner insulation so you can replace the heat energy the condensate loses as it travels on its way.

    So, three choices for you:
    1 - internal (almost zero risk)
    2 - condensate pump (very slight risk)
    3 - trace heating (done properly zero risk)

  6. Harvest Fields

    Harvest Fields S. Mod Trusted Plumber GSR Top Contributor!!

    Aren’t the chippings supposed to be charged every 12 months in a soakaway?
  7. caroldd21

    caroldd21 New Member

    Thank you so much for responding. I did have a traditional boiler which failed. This has been replaced with a Worcester Bosch 30i ERP feeding 6 radiators. Are you suggesting I can go with their horizontal pipe just below the ground suggestion if they add in a pump or trace heating? Should I be concerned about possible leakage in the future on a bend near the house? Thanks again
    • Like Like x 1
  8. caroldd21

    caroldd21 New Member

    Bosch advised me that the chippings would probably last for a couple of years but should be checked at the annual boiler check
    • Like Like x 1
  9. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    I use the soakaways , nothing wrong with them but yes it should be further away than 70 mm. Further away the better IMO .
    They are the last resort really.
  10. Harvest Fields

    Harvest Fields S. Mod Trusted Plumber GSR Top Contributor!!

    Should be 500mm from any boundary really. But sometimes this isn’t possible. At which point you should look at a condense pump.
    • Agree Agree x 1
  11. caroldd21

    caroldd21 New Member

    Thank you to everyone who responded. It appears that this was a conversation that should have been had before the boiler was sited. I did not know about the need for condensate discharge but I assume he did. Thanks again
  12. caroldd21

    caroldd21 New Member

    Just one last question - I am reading that condensate pumps can be noisy. The porch is next to the lounge. Any advice or recommendations on pump choice?
  13. Riley

    Riley S. Mod Trusted Plumber GSR Top Contributor!!

  14. caroldd21

    caroldd21 New Member

    Many thanks. I came across something called the Worcester Bosch Condensure Syphon which sounds useful. Does anyone have any experience of it?
  15. AWheating

    AWheating Trusted Plumber GSR

    condense neautraliser?
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