Rheem® PREFERRED Platinum Water Softener

42,000 Grain Large-Capacity System With WiFi Technology

The Rheem® PREFERRED Platinum™ 42,000 Grain WiFi Water Softener is ideal for all household sizes and provides soft, clean water throughout your entire home. You will also enjoy peace of mind with the free iQua™ water management smartphone app. The iQua™ app enables you to keep an eye on critical alerts such as low salt* level and continuous water flow events, as well as providing valuable information around your household water usage over time. The app also allows you to monitor, control and manually regenerate your water softener and turn off your home’s water with an optional shut-off valve. Plus, the built-in Rheem® Learning Technology optimizes overall softening efficiency by learning and adapting to your household water use.

* For peak performance in your high-efficiency Rheem water softener, evaporated salt pellets or solar salt crystals with less than 1% impurities are recommended. We do not recommend using any kind of block salt in the Rheem water softeners. Learn more.

Water Softener Savings

Rheem® Learning Technology

Learns your home’s water usage patterns to optimize salt consumption, provide on-demand soft water for your home, and maximize overall softening efficiency.


Simple Remote Water Management

Get water usage analytics, salt settings and alerts, continuous flow alerts with your mobile device using the iQua™ remote water management app. Add remote water shutoff capabilities with the optional Rheem PREFERRED™ Series Water Shut-off Valve.

Lasting Quality

Durable, high-impact salt storage with an internal double-lined mineral tank will not deteriorate, rust or corrode. The tanks are guaranteed for 10 years.

Maximum Water Pressure

Ultra high flow valve maintains water pressure in up to 1-1/4″ plumbing and homes with multiple bathrooms.

Soft and Clean Water

The built-in sediment filter keeps sediment out of your plumbing with no filter replacements needed.

Easy Salt Loading

Large tank opening with hinged cover makes loading salt fast and easy.

Ideal for All Household Sizes

Large 42,000 grain capacity ensures soft water is available when you need it for large households.

Low Salt Monitor

The iQua™ water management app and the water softener display flashes “Low Salt Level” to let you know when it’s time to add salt.

Eliminates Unsightly Stains

Removes clear water (Ferrous) iron that causes reddish-brown stains to form on toilets, showers and sinks

Made in the USA

Rheem® Water Softeners are designed, engineered and manufactured right here in the USA.

Backed with Industry-Leading Warranties

1-year on parts and labor (extendable to 5-years***), 3-years on electronics, 10-years on tanks.


*Based on findings from the Water Quality Association soft water benefits study.
**Based on the manufacturer’s internal laboratory testing.
***The 1-year can be extended to five years with the use of Rheem Cleaner – see warranty page for more information.

Rheem® PREFERRED Platinum™ Water Softener with WiFi Technology

Video Transcript

Tech Specs

RHW42 Tech specs chart. These values and more appear in a textual form in a table below.
Model CodeRH42
Rated Softening Capacity (Grains @ Salt Dose)42,400 @ 16.3 lbs.
Rated Efficiency (Grains/Pound of Salt @ Minimum Salt Dose)5,010 @ 2.5 lbs.
Rated Service Flow Rate9.9 gallons per minute (gpm)
Amount of High Capacity Ion Exchange Resin1.20 cu. ft.
Pressure Drop at Rated Service Flow12.0 pounds per square inch (psi)
Intermittent Flow Rate @ 30 psi pressure drop22.4 gpm
Water Supply Max. Hardness140 grains per gallon (gpg)
Water Supply Max. Clear Water Iron11 parts per million (ppm)
Water Pressure Limits (min. / max.)20 – 125 psi
Water Temperature Limits (min. / max.)40 – 120 °F
Minimum Water Supply Flow Rate3 gpm
Maximum Drain Flow Rate2.0 gpm
Dimensions:Height: 48″
Top View Width: 15-1/4″
Top View Depth: 20-1/2″
In and Out: 3-3/4″
Base to In and Out: 41-3/4″

Extend Your Warranty and the Life of Your Softener

A little maintenance goes a long way to ensure your water softener maintains optimal performance. Adding Rheem® Water Softener Cleaner every four months can make all the difference. Plus, with regular use, you can extend your 1-year parts and labor warranty up to 5 years.

More About Rheem Softener Cleaner
Preferred Series Water Softener Cleanser Bottle

Optional Remote Water Shut-Off Capability

Enhance your Rheem® PREFERRED Platinum™ Water Softener™ WiFi capabilities with an optional Rheem® PREFERRED™ Series Water Shut-Off Valve. Using the iQua™ app, you will be able to quickly respond to any continuous flow water alerts while away from home. Simply tap a button on your smartphone and your water supply is shut off, avoiding any potential damage to your home.

Owner Resources

Find answers to all of your water softener installation and maintenance questions

Rheem® PREFERRED Platinum™ Installation Guide

Need help installing your water softener? Follow this guide.

View Guide

Rheem® PREFERRED Platinum™ Product Manual

Use the product manual to learn everything you need to install, operate and maintain your softener.

View Product Manual