Rheem RHS32 Grain Preferred Water Softener User Manual


Rheem RHS32 Grain Preferred Water Softener User Manual


Packing List


Before You Start

  • The water softener requires a minimum water flow of 3 gallons per minute at the inlet. Maximum allowable inlet water pressure is 125 psi. If daytime pressure is over 80 psi, nighttime pressure may exceed the maximum. Use a pressure reducing valve if necessary (Adding a pressure reducing valve may reduce the flow). If your home is equipped with a back flow preventer, an expansion tank must be installed in accordance with local codes and laws.
  • The water softener works on 24V DC electrical power, supplied by a direct plug-in power supply (included). Be sure to use the included power supply and plug it into a nominal 120V, 60 Hz household outlet that is in a dry location only, grounded and properly protected by an overcurrent device such as a circuit breaker or fuse.
  • Do not use this system to treat water that is microbiologically unsafe or of unknown quality without adequate disinfection upstream or downstream of the system.
  • European Directive 2002/96/EC requires all electrical and electronic equipment to be disposed of according to Waste Electrical and Electronic Equipment (WEEE) requirements. This directive or similar laws are in place nationally and can vary from region to region. Please refer to your state and local laws for proper disposal of this equipment.

Water Conditioning Information


Iron in water can cause stains on clothing and plumbing fixtures. It can negatively affect the taste of food, drinking water, and other beverages. Iron in water is measured in parts per million (ppm). The total* ppm of iron, and type or types*, is determined by chemical analysis. Four different types of iron in water are:

  • Ferrous (clear water) iron
  • Ferric (red water) iron
  • Bacterial and organically bound iron
  • Colloidal and inorganically bound iron (ferrous or ferric)

Ferrous (clear water) iron is soluble and dissolves in water. This water softener will reduce moderate amounts of this type of iron (see specifications).** Ferrous (clear water) iron is usually detected by taking a sample of water in a clear bottle or glass. Immediately after taking, the sample is clear. As the water sample stands, it gradually clouds and turns slightly yellow or brown as air oxidizes the iron. This usually occurs in 15 to 30 minutes. When using the softener to reduce Ferrous (clear water) iron, add 5 grains to the hardness setting for every 1 ppm of Ferrous (clear water) iron. See “Set Water Hardness Number” section. Ferric (red water), and bacterial and organically bound irons are insoluble. This water softener will not remove ferric or bacterial iron. This iron is visible immediately when drawn from a faucet because it has oxidized before reaching the home. It appears as small cloudy yellow, orange, or reddish suspended particles. After the water stands for a period of time, the particles settle to the bottom of the container. Generally these irons are removed from water by filtration. Chlorination is also recommended for bacterial iron. Colloidal and inorganically bound iron is of ferric or ferrous form that will not filter or exchange out of water. This water softener will not remove colloidal iron. In some instances, treatment may improve colloidal iron water. Colloidal iron water usually has a yellow appearance when drawn. After standing for several hours, the color persists and the iron does not settle, but remains suspended in the water.


  • Sediment is fine, foreign material particles suspended in water. This water softener will not remove sediment. This material is most often clay or silt. Extreme amounts of sediment may give the water a cloudy appearance. A sediment filter installed upstream of the water softener normally corrects this situation.
  • Water may contain one or more of the four types of iron and any combination of these. Total iron is the sum of the contents.
  • Capacity to reduce clear water iron is substantiated by laboratory test data.

Installation Requirements


  • Consider all of the following when selecting an installation location for the water softener.
  • Do not locate the water softener where freezing temperatures occur. Do not attempt to treat water over 120ºF. Freezing temperatures or hot water damage voids the warranty.
  • To condition all water in the home, install the water softener close to the water supply inlet, and upstream of all other plumbing connections, except outside water pipes. Outside faucets should remain on hard water to avoid wasting conditioned water and salt.
  • A nearby drain is needed to carry away regeneration discharge (drain) water. Use a floor drain, laundry tub, sump, standpipe, or other options (check your local codes). See “Air Gap Requirements” and “Valve Drain Requirements” sections.
  • The water softener works on 24V DC electrical power, supplied by a direct plug-in power supply (included). Provide nearby a 120V, 60 Hz electrical outlet in accordance with NEC and local codes.
  • Always install the water softener between the water inlet and water heater. Any other installed water conditioning equipment should be installed between the water inlet and water softener (See Figure 4 below).
  • Avoid installing in direct sunlight. Excessive sun heat may cause distortion or other damage to nonmetallic parts.
  • Install on a flat, stable surface that evenly supports the weight of the water softener.


All plumbing must be completed in accordance with national, state and local plumbing codes.


In the state of Massachusetts: The Commonwealth of Massachusetts plumbing code 248-CMR shall be adhered to. A licensed plumber shall be used for this installation.


A drain is needed for the water discharged from the valve during the softener’s regeneration cycle (See Figure 3). A floor drain, close to the water softener, is preferred. A laundry tub, standpipe, etc. are other drain options. Secure valve drain hose in place. Leave an air gap of 1-1/2” between the end of the hose and the drain. This gap is needed to prevent backflow of sewer water into the water softener. Do not put the end of the drain hose into the drain.





Using the flexible drain hose (included), measure and cut to the length needed. Flexible drain hose is not allowed in all localities (check your plumbing codes). If local codes do not allow use of a flexible drain hose, a rigid valve drain run must be used. Purchase a compression fitting (1/4 NPT x 1/2 in. minimum tube) and 1/2″ tubing from your local hardware store. Plumb a rigid drain as needed (See Figure 6).

NOTE: Avoid drain hose runs longer than 30 feet. Avoid elevating the hose more than 8 feet above the floor. Make the valve drain line as short and direct as possible.



Always install either a single bypass valve (provided), as shown in Figure 7, or, if desired, parts for a 3 valve bypass system (not included) can be purchased and assembled, as shown in Figure 8. Bypass valves allow you to turn off water to the softener for maintenance if needed, but still have water in house pipes.


  • Copper pipe
  • Threaded pipe
  • PEX (Crosslinked Polyethylene) pipe
  • CPVC plastic pipe
  • Other pipe approved for use with potable water

IMPORTANT: Do not solder with plumbing attached to the single bypass valve. Soldering heat  will damage the plastic valve.


Installation Instructions




  • Close the main water supply valve, located near the well pump or water meter.
  • Shut off the electric or fuel supply to the water heater.
  • Open all faucets to drain all water from house pipes.

NOTE: Be sure not to drain water from the water heater, as damage to the water heater elements could result.


  • Rheem® models are factory assembled. During installation, unsnap and remove the top cover, together with the salt lid, to expose the softener valve assembly. Set them aside to prevent damage. Check the brinewell to be sure it is secured and vertical (See Figure 11).
  • Install the brine tank overflow grommet and elbow into the 13/16” diameter hole in the back of the salt storage tank wall.


  • Move the water softener into the desired location. Set it on a solid, level surface.

IMPORTANT: Do not place shims directly under the salt storage tank to level the softener. The weight of the tank, when full of water and salt, may cause the tank to fracture at the shim.

  • Visually check and remove any debris from the water softener valve inlet and outlet ports. Carefully remove the two large plastic clips (you will use them).
  • Make sure the turbine assembly spins freely in the “out” port of the valve (See Figure 10).
  • If not already done, put a light coating of silicone grease on the single bypass valve o-rings.
  • Push the single bypass valve into the softener valve as far as it will go. Snap the two large holding clips into place, from the top down as shown in Figures 12 & 13.

IMPORTANT: Be sure the clips snap firmly into place so the single bypass valve will not pull out.


Measure, cut, and loosely assemble pipe and fittings from the main water pipe to the inlet and outlet ports of the water softener valve. Be sure to keep fittings fully together, and pipes squared and straight. Be sure hard water supply pipe goes to the water softener valve inlet side.

NOTE: Inlet and outlet are marked on the water softener valve. Trace the water flow direction to be sure hard water is to inlet.

IMPORTANT: Be sure to fit, align and support all plumbing to prevent putting stress on the water softener valve inlet and outlet. Undue stress from misaligned or unsupported plumbing may cause damage to the valve. Complete the inlet and outlet plumbing for the type of pipes you will be using.



NOTE: Be sure all 3 tabs of the clip go through the matching holes on the water softener valve inlet or outlet, and fully into the channel on the single bypass valve. Make sure that the tabs are fully seated.


CAUTION: The house cold water pipe (metal only) is often used as a ground for the house electrical system, The 3-valve bypass type of installation, shown in Figure 8, will maintain ground continuity. If you use a plastic bypass valve at the unit, continuity is broken. To restore the ground, do the following:

  • Install a #4 copper wire across the removed section of main water pipe, securely clamping it at both ends (See Figure 14) – parts not included.

NOTE: Check local plumbing and electrical codes for proper installation of the ground wire. The installation must conform to them. In Massachusetts, plumbing codes of Massachusetts shall be conformed to. Consult with your licensed plumber.



To prevent air pressure in the water softener and plumbing system, complete the following steps in order:

  • Fully open two or more softened cold water faucets close to the water softener, located downstream from the water softener.
  • Place the bypass valve (single or 3 valve) into the “bypass” position. See Figures 7 & 8 on Page 7.
  • Slowly open the main water supply valve. Run until there is a steady flow from the opened faucets, with no air bubbles.
  • Place bypass valve(s) in “service” or soft water position as follows:
  • Single bypass valve: Slowly move the valve stem toward “service,” pausing several times to allow the water softener to fill with water.
  • valve bypass: Fully close the bypass valve and open the outlet valve. Slowly open the inlet valve, pausing several times to allow the water softener to fill with water.
  • After about three minutes, open a hot water faucet until there is a steady flow and there are no air bubbles, then close this faucet.

Programming the Water Softener



When the water softener is connected to electrical power, the status light above the control panel will operate as follows:

Blue status light indication Status
Flashing slowly
The salt monitor system indicates a low salt level and needs to be set. See “Set Salt Level” on Page 13.
Flashing slowly, with “CLEAn” in the display (Fig. 17)
Four months have elapsed on the system’s timer since start up or the last reset. See below.
Flashing rapidly, with “SET TIME” in the display and the clock flashing slowly
The present time needs to be set, either during initial start up or after a long power outage. See “Set Present Time of
Day”, at right.
Flashing rapidly, with “Err” in the display
The electronic self-diagnostics have detected a problem. See “Troubleshooting” on Page 19. On steady (not flashing)
The system has power and does not require any attention.


This is a reminder to use Rheem® RHWSC Water Softener Cleaner three times a year. To reset the timer, press any button on the control panel and “CLEAn” will disappear. The status light will stop flashing, unless the system is also low on salt.


When the power supply is plugged into the electrical outlet, the model code (rH32) and a software version number (example: J4.0), are briefly shown in the display. Then the words “SET TIME” appear and “12:00 PM” begins to flash.



If the words “SET TIME” do not show in the display, press the SELECT button a few times until they do.


  • Press the r UP or s DOWN buttons to set the present time. Up moves the display ahead; down sets the time back.

NOTE: Press buttons and quickly release to slowly advance the display. Hold the buttons down for fast advance.

  • When the correct time is displayed, press the SELECT button, and the display will change to show the “Hardness” screen.


If you completed the previous step, the word “HARDNESS” should show in the display. Otherwise, press the SELECT button several times until it does.


  • Press the r UP or s DOWN buttons to set the hardness of your water supply, in grains per gallon. The default is 25.

NOTE: If your water supply contains iron, compensate for it by adding to the water hardness number. For example, assume your water is
20 gpg hard and contains 2 ppm iron. Add 5 to the hardness number for each 1 ppm of iron. In this example, you would use 30 for your hardness number. 20 gpg hardness 2 ppm iron x 5 = 10 +10  (times) 30 HARDNESS NUMBER

  • When finished setting your water’s hardness number, press the SELECT button, and the display will change to show the “Recharge Time” screen.


If you completed the previous step, the words “RECHARGE TIME” should show in the display. Otherwise, press the SELECT button several times until they do.


  • The softener’s default recharge start time is 2:00 AM. This is normally a time of day when water is not being used in the household. Hard water bypasses the softener if the household draws water during the recharge cycle. If a different recharge start time is desired, press the r UP or s DOWN buttons to change the time, in 1-hour increments. Be sure AM or PM is correct.
  • When the desired recharge start time is displayed, press the SELECT button, and the display will change to show one of the salt type screens in Fig. 23.


If you completed the previous step, either “NaCl” (for Sodium Chloride) or “KCl” (for Potassium Chloride) should show in the display. Otherwise, press the SELECT button several times until one of them does.


  • Press the r UP or s DOWN buttons to set the type of salt you will be using in your water softener. The default is NaCl (standard Sodium Chloride water softener salt). If you will be using KCl (Potassium Chloride) instead, be sure to set salt type to KCl. This setting adjusts the regeneration cycle times to compensate for the different rate at which KCl dissolves. See also Page 17 for more information on salt types.
  • When the correct salt type is displayed, press the SELECT button. The display will change to show the “SET SALT LEVEL” screen.


The water softener has a status light to remind you to refill the storage tank with salt.

NOTE: You must set salt level each time salt is added  to the water softener.

To set this monitor system:

If you completed the previous step, the words “SET SALT LEVEL” should show in the display. Otherwise, press the SELECT button until they do.


Controller Features


  • 12 / 24 HOUR CLOCK
  • To set any of these options, press and hold the SELECT button for 3 seconds until “000 – -” shows in the display.


  • Then press (do not hold) SELECT again to display one of the “Salt Efficiency” screens shown below.


SALT EFFICIENCY: When this feature is ON, the water softener will operate at salt efficiencies of 4000 grains of hardness per pound of salt or higher. The softener may recharge more often using smaller salt dosage and less water. This softener is shipped with the efficiency feature set OFF. Use the r UP or s DOWN buttons to change between OFF and ON. An efficiency icon will be displayed when this feature is ON.


  • Press SELECT again to display the “Set Recharge Days” screen.


MAXIMUM DAYS BETWEEN REGENERATIONS: The electronic controller automatically determines recharge fre quency. This provides the greatest operating efficiency and, under most conditions this feature will be left in its default mode. However, you can set this feature to force a recharge every set number of days. You may want to do this if, for exam ple, your water supply contains iron and you want the softener to recharge at least once every few days to keep the resin bed clean. Use the r UP or s DOWN buttons to change the number of days (up to 15).

  • Press SELECT again to display the “12 or 24 hr” screen.


12 OR 24 HOUR CLOCK: All time displays are shown in standard clock time (1 to 12 AM; and 1 to 12 PM) at the 12 hr default setting. If 24 hour time format is desired, set to 24 hr by pressing the r UP button.

  • Press SELECT again to display the backwash time “Add” screen.


BACKWASH & FAST RINSE TIMES: If you experience salty tasting water after recharge, you may need to increase the backwash and fast rinse times. The cycle times during recharge are determined by the softener’s electronic controller. However, you may increase the backwash and fast rinse times, in 1 minute increments. If you wish to increase the backwash time, use the r UP or s DOWN buttons to add up to 15 minutes. Then press the OK button to display the fast rinse time “Add” screen.


  • If you wish to increase the fast rinse time, use their UP or s DOWN buttons to add up to 15 minutes.*
  • Press SELECT to return to the normal run (time of day) screen.


  • Setting backwash and/or fast rinse times too low may result in salty tasting water after regeneration.

Routine Maintenance


Lift the salt lid and check the salt storage level frequently. If the water softener uses all the salts before you refill it, you will experience hard water. Until you have established a refilling routine, check the salt every two or three weeks. Always add if less than 1/4 full. Be sure the brinewell cover is on.

NOTE: In humid areas, it is best to keep the salt storage level lower, and to refill more often to  avoid salt “bridging”.

Recommended Salt: Nugget, pellet or coarse solar  salts with less than 1% impurities.

Salt Not Recommended: Rock salt, high in impurities, block, granulated, table, ice melting, ice cream making salts, etc.


  • Sometimes, a hard crust or salt “bridge” forms in the brine tank. It is usually caused by high humidity or the wrong kind of salt. When the salt “bridges,” an empty space forms between the water and the salt.
  • Then, salt will not dissolve in the water to make brine. Without brine, the resin bed is not recharged and hard water will result.
  • If the storage tank is full of salt, it is difficult to tell if you have a salt bridge. A bridge may be underneath loose salt. Take a broom handle, or like tool, and  hold it next to the water softener. Measure the distance from the floor to the rim of the water softener.
  • Then, carefully push the broom handle straight down into the salt. If a hard object is felt before the pencil mark is even with the top, it is most likely a salt bridge. Carefully push into the bridge in several places to break it. Do not use any sharp or pointed objects as you may puncture the brine tank. Do not try to break the salt bridge by pounding on the outside of the salt tank. You may damage the tank.



If the softener is installed where it could freeze (summer cabin, lake home, etc.), you must drain all water from it to stop possible freeze damage. To drain the softener:

  • Close the shut-off valve on the house main water pipe, near the water meter or pressure tank.
  • Open a faucet in the soft water pipes to vent pressure in the softener.
  • Move the stem in the single bypass valve to bypass. Close the inlet and outlet valve in a 3 valve bypass system, and open the bypass valve. If you want water in the house pipes again, reopen the shut-off valve on the main water pipe.
  • Unplug the power supply at the wall outlet. Remove the softener’s top cover, together with the salt lid. Take off both drain hoses if they will interfere with moving the softener into position over the drain.
  • Carefully remove the large holding clips at the softener inlet and outlet. Separate the softener from the plastic installation adaptors, or from the bypass valve.
  • Lay a piece of 2 inch thick board near the floor drain (See Figure 38).
  • Move the softener close to the drain. Slowly and gently, tip it over until the rim rests on the wood block with the inlet and outlet over the drain. Do not allow the softener’s weight to rest on the inlet and fittings or they may break.
  • Tip the bottom of the softener up a few inches and hold until all water has drained. Leave the softener laying like this until you are ready to use it. Plug the inlet and outlet with clean rags to keep dirt, bugs, etc. out.


Model Code rH32
Rated Softening Capacity (Grains @ Salt Dose)
13,000 @ 2.6 lbs.
27,600 @ 8.3 lbs.
33,000 @ 14.1 lbs.
Rated Efficiency (Grains/Pound of Salt @ Minimum Salt Dose) 4,940 @ 2.6 lbs.
Water Used During Regeneration @ Minimum Salt Dose 1.9 gallons (7.2 L) / 1,000 grains
Total Water Used Per Regeneration @ Maximum Salt Dose 33.3 gallons (126.1 L)
Rated Service Flow Rate 7.9 gpm (29.9 lpm)
Amount of High Capacity Ion Exchange Resin 0.88 cu. ft.
Pressure Drop at Rated Service Flow 14.9 psig
Intermittent Flow Rate @ 30 psi 11.8 gpm (44.7 lpm)*
Water Supply Max. Hardness 105 gpg
Water Supply Max. Clear Water Iron 8 ppm**
Water Pressure Limits (min. / max.) 20 – 125 PSI (138 – 862 kPa)***
Water and Ambient Temperature Limits (min. / max.) 40 – 120 °F (5 – 49 °C)
Minimum Water Supply Flow Rate 3 gpm (11.4 lpm)
Maximum Drain Flow Rate 2.0 gpm (7.6 lpm)

Troubleshooting Guide


  • No soft water
  • No soft water & display is blank
  • No soft water & salt level not dropping
  • No soft water & salt storage tank full of water, water running to drain while unit is in the soft water cycle
  • Water hard sometimes Iron in water


  • No salt in the storage tank. Refill with salt and then use RECHARGE NOW feature.
  • Power supply unplugged at wall outlet, or Check for loss of power and correct. Reset electronic power cable disconnected from back of elec controls and then use RECHARGE NOW feature. tronic board or power supply malfunction.
  • Fuse blown, circuit breaker popped, or cir- Replace fuse, reset circuit breaker, or switch circuit on,cuit switched off (See “Program Memory” and then use RECHARGE NOW feature. on Page 14).
  • Electronic control board malfunction.
  • Salt storage tank “bridged”.
  • Bypass valve(s) in “bypass” position.
  • Dirty, plugged or damaged nozzle & venturi assembly
  • Inner valve fault causing leak.
  • Valve drain hose is plugged.
  • Replace electronic control board (See Page 23).
  • Refer to “Breaking a Salt Bridge” section to break.
  • Move bypass valve(s) to “service” position.
  • Take apart, clean and inspect nozzle & venturi (See “Cleaning the Nozzle & Venturi” section.
  • Replace seals and rotor.
  • Hose must not have any kinks, sharp bends or any water flow blockage (See “Valve Drain Requirements” section.
  • Disconnect tee and run separate drain lines.
  • Valve drain line and Salt Storage Tank overflow drain connected together by a tee.
  • Low or high system water pressure (low pressure may disrupt brine draw during recharge, high pressure may cause inner valve parts failure).
  • Brine float dirty or broken.
  • Leak between valve and resin tank.
  • Incorrect time set.
  • Incorrect water hardness set.
  • Incorrect model code programmed.
  • Hot water being used when softener is regenerating.
  • Possible increase in water hardness.
  • Leaking faucet or toilet valve. Excessive water usage.
  • Clear water iron in water supply. If pressure is low, increase well pump output to a mini- mum 20 psi. If daytime pressure is over 100 psi, add a pressure reducing valve in the supply pipe to the softener. Contact a licensed plumber.
  • Clean or replace Brine Valve Float Assembly.
  • Replace o-rings between resin tank and valve.
  • Check and change time setting.
  • Refer to “Set Water Hardness” section to set correctly.
  • Refer to “Program the Water Softener” section to set correctly.
  • Avoid using hot water while the softener is regenerating,  as the water heater will fill with hard water.
  • Test untreated water for hardness and iron, and program the water softener accordingly (See “Set Water Hardness”) section to set.
  • A small leak can waste hundreds of gallons of water in a few days. Fix all leaks and always fully close faucets.
  • Test untreated water for hardness and iron, and program the water softener accordingly (See “Set Water Hardness*) section to set.


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