Direct answer: If a Rheem RHS32 or RHS42 seems to have stopped softening, first measure hardness at a faucet known to receive treated water. Then check the display, bypass position, actual salt level and whether salt is being consumed. Correctly matched hardness and recharge settings matter, but a cleaner reminder is different from an error. Persistent hard water, excess tank water or an error needs a model-specific diagnosis rather than repeated resets.
Publisher boundary: Water System Guide is an independent research publisher, not Rheem water-treatment support or a repair service. These checks concern the RHS32 and RHS42 manuals Rev. P dated January 20, 2026 and current manufacturer support reviewed October 7, 2026. They organize safe owner observations; they do not diagnose a failed internal part from a symptom alone.
Confirm hard water at the right faucet
Use a hardness-specific test and follow that test kit’s instructions. Identify a cold faucet actually connected to the softened supply. An outdoor hose connection or another untreated branch may correctly test hard even when the softener is working. Rheem’s testing guidance stresses confirming the water path and says a TDS meter is not a valid hardness-performance test: the softener exchanges ions, so TDS can remain similar.
Write down the date, faucet, raw-water result if available, treated-water result and units. Repeat a surprising result with the same kit before changing settings. Soap feel, older scale deposits and a TDS reading alone do not establish whether the unit is currently delivering hard water.
After a completed recharge, compare more than one known treated cold faucet. Rheem’s No Soft Water workflow recommends that follow-up. A difference between fixtures is useful evidence about the water path; it is not proof that the resin needs replacement.
Read the display before trying a reset
The manufacturer status-light guide distinguishes the following indications for RHS32 and RHS42. Record the exact screen text and flash pattern together.
| Observation | What it tells you | Useful next step |
|---|---|---|
| Slow flash, no error text | Low salt or the monitor’s estimated level may need attention | Compare the actual salt level with its programmed level |
| Slow flash with CLEAn on RHS32 or CLn on RHS42 | Periodic cleaner reminder after four months | Follow the matched maintenance instructions; separately test hardness |
| Rapid flash with SET TIME or PRESENT TIME | Clock setup may be needed, including after an outage | Check current time and AM/PM |
| Rapid flash with Err | Electronic diagnostics detected a problem | Photograph the full code and contact support for that model |
| Display blank | Power or control needs investigation | Check the ordinary external supply only if the area is dry and safe |
A steady light does not replace a hardness test. A cleaner reminder alone does not identify the cause of hard water. For ordinary clock or salt-monitor corrections, the Rheem settings guide explains the different RHS32 and RHS42 controls.
Check whether water is bypassing treatment
The supplied push-pull bypass diagram in both manuals shows pulled out for service and pushed in for bypass. Some installations instead have a three-valve arrangement. Match what is actually installed; do not guess positions from another home’s plumbing. Do not force a stuck handle.
RHS42’s reviewed manual also describes a blending bypass valve. Its adjustment can intentionally mix some untreated water into the outlet even while the system is in service. If present, photograph the assembly and record whether an installer set a target residual hardness. The RHS42 manual, page 19 explains its adjustment and warns against overtightening. A regular bypass and a blending adjustment answer different questions.
If you cannot identify the arrangement, have the installer confirm it. Moving an unfamiliar valve is less useful than supplying a clear photo and hardness results from known treated fixtures.
Compare physical salt with the display and past use
Look through the salt lid. Record the physical level, when salt was last added and whether the level has fallen over recent recharges. Rheem’s No Soft Water workflow uses salt consumption as a troubleshooting branch. A full-looking salt tank can contain a bridge: a hardened layer above an empty space that prevents normal brine formation.
The Salt Block/Bridge article describes this condition. Do not pound the tank or use a sharp implement. If you need to break or remove a bridge, use the procedure matched to the equipment or have service handle it; pouring water into an already overfull tank is not an appropriate general test.
If the unit simply ran out of salt, add suitable softener salt and update the monitor using the model-specific salt-level procedure. RHS32 uses its SELECT menu; RHS42 uses the dedicated SET SALT LEVEL button. A displayed full level is only a monitor setting, not evidence that brine is being made.
Water standing above the salt, overflow, or drain flow continuing during normal service is a different branch. Record it and contact support or a qualified service provider. More salt or repeated recharge requests do not establish the cause. Do not disconnect drain hoses or open the pressurized valve to investigate.
If water is hard only sometimes, record when
A dated pattern helps separate settings, demand and regeneration timing. The reviewed troubleshooting tables are on RHS32 manual page 20 and RHS42 manual page 22.
| Pattern to record | What to check with support |
|---|---|
| Hard water during the scheduled recharge | Water can bypass treatment during recharge; check whether the start time overlaps household use |
| Hard water after guests or unusually heavy use | Compare the extra demand with normal use and recharge behavior |
| Hard water toward the next recharge | Retest raw hardness and confirm the programmed number, iron compensation and metering |
| Clock changes after a power interruption | Confirm the time rather than assume every setting was lost |
| Continued water use when fixtures should be off | Investigate ordinary leaks or other demand before blaming only softener capacity |
Use Rheem’s hardness instructions and our settings guide to check units and the measured feed-water value. Do not change the model code to a larger unit’s code to “add capacity.”
Rheem support’s No Soft Water process also checks water metering. If support asks for that diagnostic reading, follow its matched instructions and report whether it changes while a known treated fixture is running. Observing a reading is different from manually advancing the valve through its cycles. Leave internal turbine, wiring and valve tests to the appropriate service procedure.
When one normal recharge is appropriate
The manuals describe a manual recharge after salt was exhausted or unusually heavy water use. With salt restored and no overflow, persistent drain problem or error requiring service, the reviewed controls start an immediate recharge by holding RECHARGE for three seconds. RHS32 shows RECHARGE NOW; RHS42 shows recharge and cycle indicators. Allow the cycle to finish and then test known treated cold faucets.
A brief press instead schedules recharge at the programmed start time. These controls and indicators are explained in RHS32 manual page 15 and RHS42 manual page 15. Extra cycle features can affect duration; do not use a two-hour estimate to skip stages or interrupt a cycle.
If the follow-up test stays hard, record the result. Repeating immediate cycles without a diagnosis can obscure the pattern and consume salt and water.
Error codes need the correct model and a diagnosis
Rheem’s current Error Code article lists Err01, Err03 and Err04 as possible wiring/switch, valve or motor faults, and Err05 as a possible control-board fault. These are possible causes, not a one-code-to-one-part shopping list. The manuals use E1/E3/E4/E5 notation in their troubleshooting tables; preserve the exact notation on your own screen.
The support article reserves Err07, Err08 and Err09 for the RHW42 shutoff-valve system. They should not be imported into an RHS32/RHS42 diagnosis. This guide does not cover WiFi status on RHW42.
Internal electrical checks, valve rotation tests, part replacement and pressure-related plumbing work need the correct service procedure and skill. A reset that temporarily removes a message does not show that its cause was corrected.
Send a service record that narrows the problem
Give support or the softener service provider these items together:
- Label photo with full model and serial number, plus control and bypass photos.
- Exact error or reminder text and whether the display is flashing or blank.
- Raw and treated hardness results with units, fixture names, date and relation to the last recharge.
- Programmed hardness, salt type, clock and recharge start time.
- Physical salt level, last refill, whether salt is being consumed and any unusual tank water.
- Whether the issue affects all treated fixtures, only hot water or particular times of day.
- Last successful operation, outages, plumbing changes, unusual demand and any action already tried.
The manufacturer manual lists 1-800-754-7027 for water-treatment questions. A specific record helps support choose the right next test; it does not preselect a repair or prove that a new softener is necessary.
Frequently asked questions
Can a TDS meter show whether my Rheem softener is working?
No. Rheem says TDS is not a valid test of hardness reduction. Use a hardness-specific test at a faucet known to receive treated water, and follow the test kit instructions.
Does CLn or CLEAn mean the softener has failed?
Those messages are periodic cleaner reminders in the reviewed RHS42 and RHS32 controls. They are different from an Err indication. Test treated-water hardness separately and follow the matched maintenance instructions.
Why can a Rheem tank look full of salt but still produce hard water?
A salt bridge can leave a hardened layer above an empty space, preventing salt from forming brine normally. A displayed salt level can also be only an estimate. Check physical salt and consumption; the symptom alone does not establish the cause.
Should I keep forcing recharge if the water stays hard?
No. After an appropriate normal recharge, let it finish and test known treated cold faucets. If hardness persists, record settings, salt use, bypass position and any unusual water or code, then obtain a matched diagnosis rather than repeating cycles.
Sources and review scope
- Rheem RHS32 manufacturer-authored and manufacturer-hosted owner manual 7386465, Rev. P January 20, 2026; reviewed October 7, 2026.
- Rheem RHS42 manufacturer-authored and manufacturer-hosted owner manual 7386473, Rev. P January 20, 2026; reviewed October 7, 2026.
- Rheem first-party No Soft Water support workflow, updated February 23, 2026; reviewed October 7, 2026.
- Rheem first-party hard/soft-water testing guidance, updated February 19, 2026; reviewed October 7, 2026.
- Rheem first-party Status Light, updated February 19, 2026; reviewed October 7, 2026.
- Rheem first-party Error Code support, updated February 18, 2026; reviewed October 7, 2026.
- Rheem first-party Salt Block/Bridge support, updated March 26, 2026; reviewed October 7, 2026.
- Rheem first-party Salt Level Programming, updated February 19, 2026; reviewed October 7, 2026.
- Rheem first-party Hardness Level Programming, updated February 18, 2026; reviewed October 7, 2026.
The cited manuals and support pages were checked October 7, 2026. This review does not establish current retailer pricing, local inventory, performance in your home or the configuration of a different controller.