WaterBoss 900 36,400-Grain Water Softener Review

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The WaterBoss 900 – made in the USA – is a whole house water softener and filter with a softening capacity of 36,400 grains.

Together with the 8 gpm service flow rate, the system is ideal for mid-sized households with up to 4 people.

WaterBoss 900

WaterBoss 900

Flow Rate:8 gpm
Capacity:36,400 Grains
# of People:Up to 4
Metered Regen:

Our Rating

WaterBoss 900 Water Softener – Key Features

The former WaterBoss model 365 can soften very hard water with as much as 90 grains per gallons hardness.

It also helps to reduce iron content (less than 10 ppm) in case you are on a private well. Here, WaterBoss recommends periodic use of potassium permanganate for resin recharge.

Above that, a 20-micron pre-filter stage helps to get rid of sediment, dirt and sand to increase the system’s longevity.

The pre-filter does not require any kind of maintenance, by the way, meaning that there are no cartridges to replace.

Also, you get a 3-year limited warranty on all mechanical and electronic parts. The resin tank and outer cabinet have a 10-year limited warranty.

Minimum/maximum water pressure: 20 to 120 psi.

Some additional advice:

The WaterBoss 900 uses about 75% less salt during regeneration when performing properly. According to the manufacturer, this can be achieved if

  • Your water has a pH-value of 7 or higher.
  • The salt level in the brine tank is at least 1/3 full. If you use potassium chloride, increase your hardness setting by 12%.
  • You use a clean pellet, solar, or cube-type salt. WaterBoss advices against the use of rock salt.

WaterBoss 900 Pros

The WaterBoss 900 softener clearly has its drawbacks, but it also has some pros.

For one, it’s quiet during operation and won’t wake you up at night.

What’s more, the systems only regenerates when necessary. By measuring your water usage, it will use exactly as much salt and water as needed, so nothing is being wasted.

This is (A) good for the environment and (B) will reduce your operating cost.

And lastly, we have a certification against NSF Standard 44 for barium and radium 226/228 reduction, so you don’t have to worry about these contaminants lurking in your water anymore.

WaterBoss 900

The WaterBoss 900 – learn more on amazon.com

Installation + Startup Instructions

Thanks to the built-in bypass valve and the single-tank design which makes the unit incredibly compact, installing the WaterBoss 900 is relatively easy.

Will it be a piece of cake? No, but you also don’t have to be a licensed plumber in order to set this thing up. Required time: About one afternoon if you don’t have to make trips to your local hardware store.

Here is what you need to do:

If a softener is not equipped with a bypass valve, we recommend you provide for one for ease of maintenance. Also, make sure to comply with local plumbing codes.

1. Finding the Right Place

Before installing the model 900, make sure that there is a drain and a power outlet nearby.

Choose a location before your water heater and close to where the main water line enters your home. This way you can make sure that all the water in your house gets softened.

You should also avoid places where temperatures below zero can occur.

2. Setup

  1. Shut off your water heater and turn off its water supply.
  2. Close the main water supply valve.
  3. Open any hot and cold water taps to drain all remaining water and depressurize your plumbing system.
  4. In order to connect the water lines, lift and remove the cabinet cover.
  5. Install the Qest connection fittings (included). Attention: Qest fittings do not require the use of Teflon tape or plumber’s putty.
  6. Check the arrows on the ports to ensure correct water flow.
  7. Attach the water lines to the appliance. Be careful to not over-tighten the connections on the plastic threads.
  8. Attach the overflow elbow in down position and connect 1/2″ tubing (not included) between the overflow fitting and a suitable drain.
  9. Connect the drain line (1/2″) to the drain end cap.
  10. Route the drain line to an appropriate waste receptor. Maintain an air gap.
  11. Next, place the appliance in the Bypass position and turn on the main water supply.
  12. Open the nearest cold water faucet. Let the system flush.
  13. Place the softener in Service.
  14. Close all faucets.
  15. Check all lines and connections for leaks.
  16. Plug the softener into a power outlet.
  17. Program the system using the LCD display (more below).
  18. Add 2 gallons of water into the brine tank.
  19. Initiate a manual regeneration cycle. Allow the appliance to draw water out of the brine cabinet until the air check/draw tube sets (takes about 8–10 minutes).
  20. Press Regenerate to let the tank fill up.
  21. Fill the brine tank with salt.
  22. Turn on the electricity and water supply to the water heater.
  23. Open a cold water tap and allow the appliance to flush for 20 minutes (approx. 76 gallons).
  24. Replace the cabinet cover.

3. Video

This video explains the installation of a WaterBoss softener in more detail:

The Package (Parts)

  • Resin/brine tank (grey), 14 3/4″ x 18 3/4″ x 30 3/4″ (W x D x H), salt storage capacity 170 lbs.
  • Bypass valve
  • 36,400-grain super fine mesh resin (1 cu. ft.)
  • Self cleaning filter media
  • Water quality test strip
  • Installation kit

Programming, Settings & Maintenance

Configuring the unit’s digital control head according to your preferences can be done in under 5 minutes.

Simply enter your water hardness, the current time of the day, the regeneration time and you are good to go. Additionally, you can make other settings, such as choosing between regeneration modes and time between regen cycles.

As for maintaining the system, you should keep in mind that you have to inspect the brine tank as well as the air check/draw annually.

If you want, you can use resin cleaner on a monthly basis. Also, the system itself can be disinfected with 5.25% sodium hypochlorite.


Looking for a manual for the WaterBoss 700, 900 or 950? You can find one here: Manual

WaterBoss 900 Cons

What we don’t like is that there have been a couple of quality issues with this product, such as:

  • Damaged parts upon arrival
  • Flimsy connectors
  • Malfunctioning control heads

For a considerable proportion of users, these and other problems lead to their softening unit to just stop working after only a few months/years of use.

The overpriced replacement parts and WaterBoss’s unreliable customer service aren’t helping either.

WaterBoss 900 Review: Our Verdict

Installation might be easy and so is the programming, but taking into account the overall customer feedback, we are not sure if we can recommend the WaterBoss 900 to you guys with good conscious.

Because there definitely are mixed opinions about this softener. While some users had not have any problems in years and the unit runs perfect for them with very low salt usage, others would never by it again. Their system was a waste of money that just stopped working for no apparent reason.

Considering the fact that the WaterBoss customer support is not the best either, you better go for a softener from a different brand.

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This completes our WaterBoss 900 review. If you have any questions, please don’t hesitate to leave a comment below!

About the Author Gene Fitzgerald

Gene Fitzgerald has been with BOS since the very beginning. She is head of content creation and has fully immersed herself into the home water treatment industry only to become an expert herself. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
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