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Discuss Fitting a small undersink water heater in the Bathrooms, Showers and Wetrooms area at UKPlumbersForums.co.uk.

  1. Paul Cockhill

    Paul Cockhill Member

    Hello Everyone

    I will be fitting a vanity unit into a downstairs shower room, there is only a cold water pipe and I need to fit an undersink water heater for the hot water.

    The vanity unit will be occasional use, and I need to fit it within the vanity unit as the client does not want to see any pipework or the unit. So it needs to be small and I think a vented unit as there will be no room for an expansion vessel etc. I was looking at a Hyco Handyflow Undersink unit

    Handyflow Undersink | HYCO Manufacturing

    with a 5 litre capacity . It is a vented unit and comes with its own tap, seems ideal.

    Does anyone have any other ideas?

    With this unit you need to use their tap but the clients would really want a different tap which would not work with this unit as it needs to be vented.

    Any other ideas would be greatly appreciated. I have also looked at the Ariston water heaters, see below, which I guess would work with an ordinary tap?

    Aures Slim Multi - Electric Water Heaters - Ariston Thermo

    Many thanks

  2. Ben-gee

    Ben-gee Plumber Top Contributor!!

    Just use a little unvented undersink, you can use any tap.
    You don’t need an expansion vessel if you do the pipework to accommodate the expansion - you will however of course need a pressure relief valve and discharge from this.
    Read the manual, I have done this in the past by having a loop of speedfit of appropriate length tucked away behind the unit.
    Don’t ask them if they’d like an omelette, they probably wouldn’t want you to break any eggs!
    • Like Like x 2
  3. WC1

    WC1 Active Member

    Sorry , I meant you may need a g3 ticket for any invented cylinder. Instant , non storage as you had originally is good
    • Winner Winner x 1
    Last edited: Jun 9, 2019
  4. Paul Cockhill

    Paul Cockhill Member

    Thanks, yes I have a G3 ticket, but I have little room to work with so just want a basic vented undersink tap
  5. WC1

    WC1 Active Member

    In a very small, (micro) kitchen - John strand stuff, I have once run a snake of 22mm copper at the side of a kitchen cupboard with streets and elbows to accommodate expansion. from memory it was 1.4 metres as per mi's . Bit of a faff but got it done within regs and mi's.
    • Agree Agree x 1
  6. Paul Cockhill

    Paul Cockhill Member

    Thanks for the update. Looks like a good idea and then they could use there own tap
  7. Ben-gee

    Ben-gee Plumber Top Contributor!!

    pretty sure i just said all that!

    and you don't need g3 for those little ones.
    • Agree Agree x 2
  8. WC1

    WC1 Active Member

    Hi Ben, I wouldn't go for plastic near any heater, on the hot or cold side. I believe you do need g3 even for little ones. There's a thread somewhere.
  9. WC1

    WC1 Active Member

  10. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    you do need to be g3 registered
  11. WC1

    WC1 Active Member

    It was a shock to me!
  12. Ben-gee

    Ben-gee Plumber Top Contributor!!

    ah ok my mistake, i thought it was not required up to 10litres - I must have that wrong or maybe it's changed within living memory.
    I s'pose I need to get my G3 ticket in that case, then I can graduate to the bigger ones too. Lots of people want them these days, including me at home in near(ish) future...
    • Agree Agree x 1
  13. DuncanM

    DuncanM Plumber GSR

    Pretty sure it is 10 or 15 L without unvented ticket
  14. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    Nope need qualification only difference you don’t need to register install with bc
  15. rpm

    rpm Trusted Plumber Top Contributor!!

    Does that apply to the likes of these hot taps?
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