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CH boiler replacement . System or open vent?

Discussion in 'Plumbing and Central Heating' started by elmsoft, 9 Jun 2020.

  1. elmsoft

    elmsoft

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    I'm planning on upgrading my CH boiler, currently an open vent set-up with header tank etc. I don't want a combi but a sealed system seems simpler, an obvious choice. Why would I bother with a header tank if I don't have to?
    Is there any advantage of header tank /open vent set-ups or are they just a hangover from the past?
     
  2. ianmcd

    ianmcd

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    An open vent constantly fills your system if you have a leak, a sealed system will shut down if you have a leak, changing from open vent to sealed can actually cause leaks, because they operate under different pressures, speak to your installer and see what he /she recommends, the choice of boilers if you go with sealed systems is far greater than open vent systems, as sealed systems are the norm these days
     
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  4. elmsoft

    elmsoft

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    Sounds like a comprehensive reply. :) Thank you. I guess if I have a leak I would want to know. And even if it is a weakness that might leak, probably as well to find it now. :)

    Thank you.
     
  5. WestmidsDIY

    WestmidsDIY

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    If you have any heating pipes in concrete floors or hard to access, open vent is the better option..
     
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  7. ScottishGasMan

    ScottishGasMan

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    A properly fitted and treated open vent system is in my mind the most reliable you will get. Different factors come into play such as age of system and access to pipework and budget, as once you pressurise it, if there are problems then its too late to go back, you can end up having to replace a lot of pipework or fittings.

    That being said, lots of systems convert over no problem, the issue is theres no way to know for sure before you do. Make sure if you do go down the sealed route that the expansion vessel fitted is big enough. Its the most common installtion fault you get nowadays when fitters rely on a built in vessel thats often not big enough for a system, which will cause all sorts of issues.
     
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