[b]Unvented HW system - servicing[/b]

Discussion in 'Plumbers' Talk' started by nuthatch, Jul 14, 2005.

  1. nuthatch

    nuthatch New Member

    I am cannot decide whether to go for an open vented, or an unvented hot water system ... I understand the pros and cons of each; one of the cons of an unvented system being (as far as I know) that it must be serviced/checked annually. Is this correct? Is it essential - for safety reasons or what?
    If so, is it possible to do this myself? I mean what service does it actually need?
    If I have to get a plumber or engineer in each year to do this, then long term it will not be very cost effective, and the cons will then outweigh the pros! Incidentally, roughly what would be the normal charge for this service?
    I realise of course that it would have to be installed by a qualified fitter with the neccessary 'ticket', but it would be done same time as installing a brand new central heating system.

    Any advice much appreciated
  2. The servicing must be done by a quailfied plumber, the same as your gas boiler is done by a quailfied (corgi) engineer.

    Given the choice I'd go for unvented every time.

    No-one will force you to get your applinaces (boiler/cylinder) serviced each year, but all manufactures will recommend this, so as a corgi enginneer i'd recommend you have appliances serviced each year.
  3. plummit

    plummit New Member

    Hi SpikeBmth

    What does a service of an unvented system consist of?. Is it purely checking the exterior/ interior expansion vessels, and checking pressure/temp valves.
    Cheers Mate.
  4. basically yes, as well as a trained eye casting itself over the cylinder!!
  5. plummit

    plummit New Member

    Where can I buy one of these trained eyes ?? lol.
  6. I got mine at the unvented water college!
  7. doitall

    doitall New Member

    I got mine at the unvented water college!

    Would that be Poole mariner.

    "hello Sailor" ;);)
  8. close, actually Portsmouth! Still very nautical! Captain pugwash & his crew! :)
  9. nuthatch

    nuthatch New Member

    Spike .. Thanks for reply.

    Any idea what a service for unvented HW system might cost? Even a rough estimate would help .... as I have to decide if the extra cost of servicing each year outweighs any advantage I might get from an unvented system.
    I mean; are there any REAL significant advantages over open vented?? Or is it just that installation is easier for plumbers?
    Incidentally, is the service neccessary on safety grounds?
  10. LarryPlum

    LarryPlum New Member

    Apart from the servicing issue, just make sure you've got a 22 or 25mm incoming water main. All unvented cylinder manufacturers specify this as an installation requirement and if you've got a couple of bathrooms and an en-suite you'll certainly notice the difference.

    I've been asked to fit unvented systems in large houses and refused unless the customer gets their water main upgraded from an old 1/2". When they find out what this can cost, this they are often happy to go for the open vented system.
  11. LarryPlum

    LarryPlum New Member

    Whoops - just noticed your other thread nuthatch - all covered on there I see.
  12. Moley

    Moley New Member

    something else you will need to consider when fitting an unvented cylinder is the discharge pipework. This may be a problem if you airing cupboard is not near an outside wall.
  13. I can't say how much it'd cost to do teh annual check on an unvented system. We check our contract customers unvented systems at same time as annual boiler check, but as there contract includes the cylinder, make no extra charge. It is important for safety to check that safety valves are operating ok, as part of the check. As i said before I can only go along with maunfactures recommenadations of both boilers & unvented cylinders and suggest they are checked on an annual basis.
  14. nuthatch

    nuthatch New Member

    Hi LarryPlum
    Many thanks for your useful advice which is much appreciated. I'm grateful for all the advice I get, and particularly interested in your last paragraph. It's good to see that you are honest with your customers, in telling them that in such a situation they would be better off with open vented.
    So going by your advice re pipe sizing, it looks as if my mains supply would be OK for unvented.
    As you rightly said, I did mention pipe sizes in another thread (thought it would be better to keep the two subjects separate - oh well!!)
    Thanks again
  15. nuthatch

    nuthatch New Member

    Cheers Spike ... that's a help anyway. Your advice always appreciated.

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