FOUNTAIN VALLEY, Calif. — Tankless water heater manufacturer Noritz America released an updated version of its hard water-treatment product, Scale Shield. 

The original Scale Shield aids in preventing the build-up of hard water minerals while eliminating the need for a water softener. Hard water contains dissolved calcium and magnesium that, when heated, are released in the form of a chalk-like material. This chalk coats pipes, fixtures, and fittings, creating an insulating layer that leads to lower efficiency and system malfunction.

Installed in the water heater’s water supply line, Scale Shield uses a polyphosphate material to sequester calcium before entering the water heater, preventing limescale from forming. The calcium is rendered harmless and is discarded down the drain. Scale Shield offers time savings and cost savings while reducing the footprint inside the home — all attractive benefits.

Noritz has taken this original Scale Shield and incorporated innovations to bring this superior product to the next level with the following upgrades: 

  • Sediment filter: Built into the new Scale Shield, a sediment filter removes particulate matter from the water. This 5-micron filter sifts through the debris while introducing the polyphosphate additive to the water. This additive coats the calcium particulates, preventing them from releasing from the water when heated; instead, they go harmlessly down the drain.
  • Cartridge gauge: Two pressure gauges allow the homeowner to check pressure levels manually. As the particulate matter and debris collect within the filter, the buildup causes water pressure loss in the house, indicating a replacement filter is needed. To replace the filter, the homeowner simply unscrews the housing, removes the old cartridge, and replaces it with a new one.
  • Efficient material for water treatment: The new Scale Shield also uses a different treatment medium than its predecessor. A bead-like material replaces the original’s powdery substance, increasing the efficiency of water treatment and reducing corrosion caused by chlorides, silica, and dissolved iron. Although Noritz recommends a 12-month replacement timeframe at 15-grain hard water or less, the increase in media size offers a slightly extended lifespan for the product.
  • Compatibility and connections: The new Scale Shield is compatible with all Noritz residential tankless water heaters and combination-boiler models. It contains 0.75-inch stainless NPT inlet and outlet connections and, as previously noted, connects the cold water supply line to the tankless water heater.
  • Cost benefits: Cost savings are provided through lower maintenance costs and a reduced need to periodically descale their Noritz tankless water heaters — even in locales with seriously hard water. 


By reducing limescale, the new Scale Shield inevitably boosts the unit’s longevity while also minimizing scale build-up in other plumbing fixtures and fittings, thus lowering cleaning and other maintenance expenses.

“Installing Scale Shield is a significantly smaller cost burden than replacing your water heater’s heat exchanger due to excessive scale build-up,” said Randall Oshiro, lead engineer, Noritz. “All of these cost and time savings, without a doubt, greatly enhance the value of a tankless water heater investment.”

In addition, IAPMO/ANSI Z601 was created to enable testing on means and methods used to reduce scale in residential water heaters. A minimum of 70% reduction in scale formed in a hot water heater and downstream piping is required. The glassy polyphosphate used in the enhanced Scale Shield passed the IAPMO/ANSI Z601 Standard with 86% scale removal.

The updated Scale Shield is sold in a kit (SS-HB-3) and includes a wall bracket, wrench, lubrikit, pressure gauge, and one HBC-3 cartridge. Individual cartridge replacements can be found on the website as well. For more information, visit