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Scalecutter. Do I need it?

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GeoJar
GeoJar Member Posts: 1
in Water Quality

I recently installed a Rinnai I-Series Condensing Gas Combi Boiler. A Scalecutter housing & cartridge are listed in the manual as accessories. Would this be intended primarily to protect the DHW or CH, heat exchanger? Or for both? My well water tested at about 105 mg/L Calcium Hardness, so would I even benefit from installing it?

Thanks for the advice!

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  • Big Ed_4
    Big Ed_4 Member Posts: 3,515
    edited February 9

    It is to help preventing the hot water plate heat exchanger from plugging up …

    There was an error rendering this rich post.

  • hot_rod
    hot_rod Member Posts: 27,329

    Rinnai shows a water quality spec for the water in the boiler itself. Also a mention of using the scale cutter, but no water spec for the potable water side.

    6 GPG is not too bad for hardness, but an occasional flush of the HX never hurts

    If you install the isolation flush valves, Rinnai offers them and may other brands, it is an easy task to clean the plate HX.

    Screenshot 2026-02-09 at 2.48.18 PM.png Screenshot 2026-02-09 at 2.47.42 PM.png
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream

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