Rheem Water Softener Specs — Grain, Iron & Warranty

Quick answer

Rheem's published softener lineup covers 4 models spanning 18,000 to 42,000 grains, all demand-initiated (metered) regeneration. Every figure below is captured from official Rheem sources with the link shown — match any model's grain rating against your requirement from the size calculator before comparing anything else.

Rheem softener lineup at a glance

Rheem publishes some of the highest clear-water iron ratings in its class — up to 11 ppm on the models below. If you are on an iron-bearing well, that ceiling (not grain capacity alone) decides whether Rheem is even a candidate: check it against your tested iron, then the tier against the size calculator.

Every figure traces to an official Rheem source (linked per table); anything the sources don't state is marked "(to be verified)" rather than guessed.

Rheem Rheem Preferred Series (RHS line + Platinum wifi) (Residential)

RHS32 (Preferred 32,000) — official spec notes: efficiency 4,940 grains/lb @2.6 lbs; max hardness 105 gpg; resin 0.88 cu ft; intermittent 11.8 gpm @30psi; 43.5H x 15.25W x 20.5D in.

RHS42 (Preferred Plus 42,000) — official spec notes: efficiency 5,010 grains/lb @2.5 lbs; max hardness 140 gpg; resin 1.20 cu ft; intermittent 22.4 gpm @30psi; 48H x 15.25W x 20.5D in.

How to read these specs against your sizing

Three checks before buying any Rheem model: first, get your required rated capacity from the size calculator (hardness + household + iron); second, verify the model's rated iron limit exceeds your tested iron — same-tier models differ here more than anywhere else; third, confirm service flow rate covers your peak simultaneous use (bathrooms × 3–4 GPM as a working figure). The warranty column rewards a slow read: tank, valve and electronics terms are listed separately by most brands and they are not equal.

Salt and maintenance context

Whatever the tier, running cost is mostly salt: expect on the order of 40–80 lb per month for an average household (the regeneration calculator computes it for your exact load), plus an occasional resin cleaner where iron is present. Every model in the current Rheem lineup regenerates on demand (metered), which tracks actual water use rather than a calendar — the feature that keeps salt bills honest.

Which Rheem tier fits which household

At 15 gpg (very common hard water), the Rheem lineup covers: a couple (needs ≈ 21,000 grains rated) → 32,000-grain; a family of four (≈ 42,000) → 42,000-grain; a family of six (≈ 63,000) → outside this lineup. Six-person households on very hard water generally outgrow single-tank retail units — a duplex system or the next brand tier up serves better. Different hardness moves these fast: every ±5 gpg shifts a typical family one tier — see the sizing chart for the full matrix.

This page is independent — no affiliation with Rheem; brand names are trademarks of their owners. Compare Rheem side by side with other brands on the brand index.