Rinnai R85 Tankless Water Heater

    Rinnai R85 Specs

    Tankless Specs


    Hot water capacity Minimum flow – 0.5 gpm (gallons per minute)

    – Maximum flow – 5.3 gpm

    Anticipated maximum – at 75°F temperature rise (input 45°, output 120°) 4.2 gpm

    There should be no single water fixture requiring more than 3.5 gpm

    Sized right for our Ontario climate

    Input BTU rating: Minimum 15,000 Maximum 180,000

    Efficiency rating: 82%

    Installation requirements

    Water lines – minimum ¾” required (inlet & outlet) – R-Ready Valve Set included

    Gas lines – sized for 180,000 BTU rating (3/4” minimum, larger with long runs)

    Gas pressure – minimum 6” W.C. (watch low pressure areas)

    Water pressure – target 30 – 80 psi (minimum 15 psi, maximum 150 psi)

    No anti-scald mixing valve required (check with your local municipality)

    Venting – 5” concentric venting (proprietary to Rinnai)

    Outside wall location is recommended – Standard Vent Kit included

    Application guidelines

    Hard water areas

    Unit is approved for use in areas where the water hardness is less than 12 grains

    Typically, GTA, Ottawa and Niagara municipal water sources qualify

    North (Barrie) and southwestern Ontario likely not eligible

    For hard water areas above 12 grains, please discuss with installation crew. A water softener may be required.


    No re- circulating systems permitted (holding tanks, plumbing re-circ, etc.)

    Author: John

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    1. Does the R85 use a lot of natural gas,?
      How often should R85 be flushed out?

    2. Given that we’re in Canada, how about providing metric specifications? Rather than making us do all the necessary conversions ourselves into more understandable units.

      Not everyone shopping for these things is over 50, which is about the age of folks who last saw the imperial system used in Canada. Canada has been metric since 1972. The school systems have been teaching metric since before that. The only country in the world today that isn’t metric is the USA. Even the UK has all these specs in metric – in addition to having far more choice, but that’s another matter. Also, most safety and building specifications and documents relating to standards are METRIC in Canada.

      So please, how about providing the metric specifications for these products?

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