Rheem RHS42 - User Manual

Questions and Answers

M
Matthew MorrisAug 17, 2025
What to do if my Rheem RHS42 Water Dispenser has no soft water and the display is blank?
- M
  Meghan BenderAug 17, 2025
  If your Rheem Water Dispenser shows no soft water and the display is blank, first check for any power loss at the wall outlet or a disconnected power cable at the back of the electronic board. Correct any power issues and reset the electronic controls. Then use the RECHARGE NOW feature. Also, check the fuse, circuit breaker, or circuit switch. Replace the fuse, reset the circuit breaker, or switch the circuit on, and then use the RECHARGE NOW feature. If the issue persists, the electronic control board may be malfunctioning, and you may need to replace it.
R
rwilsonAug 20, 2025
Why is my Rheem RHS42 Water Dispenser sometimes dispensing hard water?
- M
  Michael FletcherAug 20, 2025
  If your Rheem Water Dispenser is sometimes dispensing hard water, check if the time is set correctly and change the time setting if it's incorrect. Also, you should check if the water hardness is set correctly. Hot water usage during regeneration can also cause this issue, so avoid using hot water while the softener is regenerating. A leaking faucet or toilet valve can also cause the issue, so fix any leaks and always fully close faucets.
M
michealjacksonAug 23, 2025
What to do if my Rheem RHS42 has no soft water and the salt level isn't dropping?
- K
  Kimberly YoungAug 23, 2025
  If your Rheem Water Dispenser has no soft water and the salt level isn't dropping, the salt storage tank may be bridged. Refer to the “Breaking a Salt Bridge” section to break it. Additionally, check if the bypass valve(s) are in the “bypass” position and move them to the “service” position.
J
John Martinez MDAug 28, 2025
How to remove iron from water using Rheem Water Dispenser?
- J
  Jonathan MasonAug 28, 2025
  If you notice iron in the water from your Rheem Water Dispenser, test the untreated water for hardness and iron, and program the water softener accordingly. If there is iron in soft water, clean the resin bed with Resin Bed Cleaner, following the instructions on the package. Note that bacterial or organic bound iron cannot be treated by a water softener.
B
Brian HuertaAug 30, 2025
What to do if the status light is off on my Rheem RHS42 Water Dispenser, but the display is not blank?
- V
  Veronica BakerAug 31, 2025
  If the status light is off on your Rheem Water Dispenser, but the display is not blank, the status light may have dislodged from its holder. Remove the top cover and reinsert the status light into its holder.
S
Samantha WallsSep 2, 2025
Why is there resin in my Rheem Water Dispenser plumbing?
- T
  Traci HorneSep 3, 2025
  If you find resin in your household plumbing connected to the Rheem Water Dispenser, it could be due to a crack in the distributor or riser tube. Replace the resin tank assembly.
M
Miss Amy HunterSep 5, 2025
What causes the salt storage tank of Rheem RHS42 to leak?
- B
  Brendan AcevedoSep 5, 2025
  If the salt storage tank of your Rheem Water Dispenser is leaking, it is likely due to a crack in the brine tank. Replace the salt storage tank assembly.
A
Anna GraySep 8, 2025
Why is the motor stalled or clicking on my Rheem RHS42?
- C
  Cody HarrisonSep 8, 2025
  If your Rheem Water Dispenser's motor is stalled or clicking, it could be due to a motor malfunction or an internal valve fault causing high torque on the motor. You can try replacing the rotor/seal, or replacing the motor and switch.
K
Kristin HaasSep 12, 2025
What does error code E1, E3, or E4 mean on my Rheem Water Dispenser?
- N
  nancy58Sep 12, 2025
  If error code E1, E3, or E4 appears on your Rheem Water Dispenser, it could indicate a fault in the wiring harness or connections to the position switch. Try replacing the wiring harness or connections to the position switch. Alternatively, there may be a fault in the switch itself, in which case you should replace the switch. A fault in the valve causing high torque, or an inoperative motor, could also cause these errors, so replace the rotor/seal or the motor as needed.
T
Tammy Rogers DDSSep 13, 2025
What does error code E5 mean on Rheem RHS42?
- H
  Helen Sparks MDSep 13, 2025
  If error code E5 appears on your Rheem Water Dispenser, it indicates an electronic control malfunction. Replace the electronic control board.

Summary

Product Overview and Specifications

Specifications and Performance Claims

Details performance metrics like capacity, efficiency, flow rates, and pressure limits.

Model RHS42 Performance Data

Details performance metrics like capacity, efficiency, flow rates, and pressure limits.

Controller Operations and Features

Programming the Water Softener

Explains status lights and guides on setting the current time on the controller.

Status Lights and Initial Time Setup

Explains status lights and guides on setting the current time on the controller.

Controller Settings Configuration

Guides on setting water hardness, regeneration start time, and salt type.

Water Hardness, Recharge, and Salt Type

Guides on setting water hardness, regeneration start time, and salt type.

Controller Features - Recharge and Monitoring

Explains manual recharge options and the salt monitor system.

Recharge Functions and Salt Monitoring

Explains manual recharge options and the salt monitor system.

Controller Features - Optional Settings

Details how to configure Salt Efficiency, Clean Feature, and Clean Feature Minutes.

Controller Features - Cycle Timing

Regeneration and Time Adjustments

Controller Features - Display and Memory

Maintenance, Troubleshooting, and Parts

Bypass Blending Valve Operation

Adding Salt and Breaking Salt Bridges

Cleaning Components and Freeze Protection

Troubleshooting Guide

Provides causes and corrections for common issues.

Common Problem Resolution

Provides causes and corrections for common issues.

Troubleshooting - Diagnostics and Reset

Explains manual diagnostics and resetting the unit.

Electronic Diagnostics and Factory Reset

Explains manual diagnostics and resetting the unit.

Troubleshooting - Recharge Checks

Verifies operation of valve motor, brine fill, and recharge rates.

Manual Advance Recharge Cycle Verification

Verifies operation of valve motor, brine fill, and recharge rates.

This document is an installation and operation manual for the Rheem Model RHS42 Demand Controlled Water Softener.

Function Description

The Rheem Model RHS42 is a demand-initiated regeneration (D.I.R.) water softener designed to reduce water hardness, barium, and radium 226/228. It also has a capacity to reduce clear water iron. The system uses an electronic controller to manage regeneration cycles based on water usage, optimizing salt and water consumption. It features a variable salt dose, meaning the salt amount for regeneration is selected by the electronic controls based on the actual need. The softener is designed to provide soft water for at least ten continuous minutes at its rated service flow rate.

Important Technical Specifications

Model Code: rH42
Rated Softening Capacity:
- 12,400 grains @ 2.5 lbs. salt dose
- 29,900 grains @ 8.0 lbs. salt dose
- 42,400 grains @ 16.3 lbs. salt dose
Rated Efficiency (Grains/Pound of Salt @ Minimum Salt Dose): 5,010 @ 2.5 lbs.
Water Used During Regeneration @ Minimum Salt Dose: 2.5 gallons / 1,000 grains
Total Water Used Per Regeneration @ Maximum Salt Dose: 45.9 gallons
Rated Service Flow Rate: 9.9 gpm
Amount of High Capacity Ion Exchange Resin: 1.20 cu. ft.
Pressure Drop at Rated Service Flow: 12.0 psig
Intermittent Flow Rate @ 30 psi: 22.4 gpm (Note: This does not represent the maximum service flow rate for determining rated capacity and efficiency. Continuous operation at higher flow rates may affect performance.)
Water Supply Max. Hardness: 140 gpg
Water Supply Max. Clear Water Iron: 11 ppm (Note: Capacity to reduce clear water iron is substantiated by laboratory test data. The State of Wisconsin requires additional treatment if water supply contains clear water iron exceeding 5 ppm.)
Water Pressure Limits (min. / max.): 20 - 125 PSI
Water and Ambient Temperature Limits (min. / max.): 40 - 120 °F (Do not attempt to treat water over 120°F or install where freezing temperatures occur, as this voids the warranty.)
Minimum Water Supply Flow Rate: 3 gpm
Maximum Drain Flow Rate: 2.0 gpm
Electrical Power: 24V DC, supplied by a direct plug-in power supply (included). Requires a nominal 120V, 60 Hz household outlet.
Dimensions:
- Height: 48 inches
- Width: 20-1/2 inches
- Depth: 15-1/4 inches
- Inlet/Outlet Spacing: 3-3/4 inches
Certifications: System tested and certified by NSF International against NSF/ANSI Standard 44 for hardness reduction, efficiency, barium, and radium 226/228 reduction, and certified to NSF/ANSI Standard 372.

Usage Features

Demand Controlled Regeneration: The system regenerates based on actual water usage, minimizing salt and water waste.
Salt Efficiency Feature: Can be set to ON (required in California) to operate at salt efficiencies of 4000 grains per pound of salt or higher, potentially leading to more frequent recharges with smaller salt doses.
Controller Programming:
- Set Present Time of Day: Allows users to set the current time.
- Set Water Hardness Number: Users input their water hardness (adding 5 grains for every 1 ppm of ferrous iron).
- Set Recharge Start Time: Default is 2:00 AM, but can be adjusted.
- Set Salt Type: Can be set for NaCl (sodium chloride) or KCl (potassium chloride).
Manual Regeneration Options:
- Recharge Now: Initiates an immediate regeneration cycle (approx. 2 hours).
- Recharge Tonight: Schedules regeneration for the next preset recharge time.
Salt Monitor System: Features a status light and display bars (0-8) to indicate salt level in the storage tank. Users must set the salt level after adding salt.
Tank Light: A button on the faceplate turns on a light inside the salt storage tank for 15 minutes or until turned off.
Water Flow Indicator: Displays scrolling bars to show soft water flow rate.
Recharge Time Remaining & Valve Position Indicators: Shows the current stage of regeneration (Serv, Fill, Brine, Bkwsh, Rinse) and the remaining time.
Bypass Blending Valve: A unique push-pull bypass valve that allows fine adjustment of treated water hardness by diverting a small stream of hard water to blend with the softened water. It can also be used to bypass the softener for maintenance while still providing water to the house.
Cleansing Feature: An optional feature that performs an extra backwash and fast rinse cycle before normal regeneration. This helps collect larger sediment particles (sand, silt, dirt) in an integrated basket and rinse them to the drain, providing added protection for water-using appliances. It is recommended for water supplies containing iron and/or high amounts of sediments.

Maintenance Features

Salt Addition: Users should frequently check the salt storage level (every two to three weeks, or when less than 1/4 full) and refill with nugget, pellet, or coarse solar salts with less than 1% impurities.
Breaking a Salt Bridge: Instructions are provided for identifying and breaking a "salt bridge" (a hard crust of salt that prevents it from dissolving) using a broom handle.
Nozzle & Venturi Cleaning: Detailed steps are provided for disassembling, cleaning, and reassembling the nozzle and venturi assembly, which is crucial for proper brine draw and softener operation.
Freezing Protection: Instructions are given for draining the water softener to prevent freeze damage if it's installed in an unheated area.
Product and Warranty Registration: Users are encouraged to register their product online to validate and extend the warranty. The standard one-year full warranty can be extended to five years if Rheem® RHWSC Water Softener Cleaner is used as directed and registered.
Troubleshooting Guide: A comprehensive guide addresses common problems (e.g., no soft water, salt level not dropping, water hard sometimes, iron in water, error codes) with corresponding causes and corrections.
Manual Advance Recharge Check: Allows users to manually cycle through regeneration stages to verify proper operation of the valve motor, brine tank fill, brine draw, and flow rates.
Electronic Diagnostics: Users can access a diagnostic display to view turbine count (water flow), valve cycle position, and position switch status.
Reset to Factory Defaults: Instructions are provided to reset the electronic controller to its original factory settings.

Rheem RHS42 Specifications

General

Brand	Rheem
Model	RHS42
Category	Water Dispenser
Language	English

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Rheem RHS42 - User Manual

Table of Contents

Questions and Answers

Summary

Product Overview and Specifications

Specifications and Performance Claims

Model RHS42 Performance Data

Installation Guide

Before You Start

Installation Prerequisites and Safety

Installation Requirements

Location, Plumbing, and Air Gaps

Installation Instructions - Initial Steps

Water Supply, Assembly, and Placement

Installation Instructions - Plumbing

Connecting Inlet and Outlet Lines

Installation Instructions - Testing and Finalizing

Grounding, Draining, and Leak Testing

Installation Instructions - Finalizing

Sanitization and Power Up