The Rinnai scale cutter can be used with Tankless Water Heaters and Combi Boilers. It works by simply preventing the amount of minerals found in potable water to prevent lime-scale buildup and corrosion that can diminish hot water performance within the appliance. The Scale Cutter offers similar benefits of traditional water softeners.
Scale cutter system unit 3/4 in. water conditioning system
For use with Rinnai Tankless water heaters
Dimensions: 5.18 in. x 13.34 in. x 4.78 in.
Water heater accessory
Country of origin: United States
For use with SENSEI SE+ tankless water heaters (condensing) and m-series boilers
Package quantity 1
1 year limited warranty
*Note. Rinnai is changing the language in its warranty terms and conditions found in the current User Installation manuals. The existing statement will be replaced by the following: "This Limited Warranty applies only to products that are installed in the United States and Canada. Improper installation may void this Limited Warranty. It is recommended that a trained and qualified professional who has attended a Rinnai installation training class complete your installation." All warranties (old or new manual) will be honored as written above.
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Product Depth (in.)
Product Height (in.)
Product Width (in.)
For Use With
Supply Line Softener
Product Weight (lb.)
Warranty / Certifications
1 Year limited warranty
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Aug 27, 2020
May 30, 2020
If you read the installation and warranty for the Rinnai on-demand hot water heater, this is requ...
If you read the installation and warranty for the Rinnai on-demand hot water heater, this is required for hard water sites. The warranty is void for damage caused by unfiltered hard water. The distributor / installer claimed to have no idea what I was talking about, leading me to suspect that he was just setting up his customers for downstream repair work or unit replacements, which for him would be far more profitable than installing a filter. I bought this on my own and had it installed; whether it works satisfactory or not won't become evident for at least 6 months, but at least my new hot water system now conforms to the warranty requirements. Only drawback is that it should not be in direct sunlight (which is not in the specifications but only disclosed in the installation package), so I had to revise installation worksite to accommodate that requirement. It's been installed and working for about one month.