AO-Smith Water Softener Injector & Filter

Inlet Filter Location & Repair
Injector Parts

Injector Filter on an A.O. Smith 400T Water Softeners

The water softener injector or eductor is a venturi device that creates the suction to draw brine from the water softener brine tank and to inject that brine into the water softener's resin tank.

Symptoms of eductor or injector trouble

If the injector/eductor is clogged you may find that the softener does not draw brine from the brine tank and even though the softener goes through a regeneration cycle, it stops softening your water supply. You may also find abnormally high water levels in the brine tank.

Where to Find the Injector on an AOS Softener

The injector for your AOS water softener (and most water softeners) is located in the control head (shown above) OR in the brine tank at the top of the brine tank float well as part of the plastic valve found on the brine pick-up tube - shown in the illustration just below, using the AO Smith Triasoft Midi water softener as an example.

That's the case with nearly all water softeners, although the exact location on the control head and its manner of removal varies by softener brand and model.

On your softener, as you'll see in our annotated sketch, located on the front center of the control and is accessed beneath a cap held in place by three screws. (On some other water softener brands and models the injector is more-easily accessed by a plastic screw-on cap.)

How to Clean or Replace the Injector on an AO Smith Softener

Remember that before attempting to disassemble and clean the injector (or replace it) you need to put the water softener into bypass mode and start a regeneration cycle to remove water pressure from the control head.

In removing, cleaning, and replacing the water softener injector take care not to damage or lose the O-rings and if cleaning the small opening in the injector itself take care not to gouge or enlarge or damage it.

If the injector screen can't be cleaned or is badly corroded or damaged it should be replaced.

Below is an AO Smith water softener inlet filter, about $17. from typical suppliers.

The manual for your AO Smith 400t water softener is given as a free PDF download above on this page.

That manual describes the filter as

It features a built-in dirt and sediment filter and fine mesh resin that reduces scale buildup on internal pipes and plumbing.

You're quite right to ask where that filter is found since a look at the AOS Water softener instructions finds not one bit of detail about filter replacement or maintenance - if you search for the word "filter".

But the cover of the instruction booklet says

Use this owner’s manual to reference installation, troubleshooting and filter replacement information.

If you need help ... call 855.424.9892

The AO Smith softener instructions tell owners to clean or replace the injector assembly under various problem conditions but don't trouble themselves to give even the slightest hint how to do so nor to point to its location.

Perhaps that's because the company figures that you should be hiring a trained water service technician. But indeed many homeowners are up to the task of cleaning a water softener injector or eductor.

We describe replacing, repairing, or cleaning the water softener injector - called the "Eductor" in some manuals,

at WATER SOFTENER EDUCTOR / INJECTOR REPAIR

using a Culligan HE 1.25 water softener as an example.

The principle and types of parts are the same but the exact location and assembly varies among water softener brands such as those for your AO Smith softener - described above.

To be clear, pretty much every water softener has more than one filter or screen, including the injector screen found in the brine tank and a resin screen usually at the bottom of the resin bed in the resin tank.

AO Smith / Water Right Injector Assembly Parts

Below: Parts explosion for the injector assembly on a Water Right Impression Series water softener listed by A.O. Smith several middle-eastern countries including Egypt and Saudi Arabia, Jordan, Kuwait, UAE, Oman, Bahrain and Qatar.

This model provide a screw-off cap over the softener's injector screen and plug.

• Contact: A. O. Smith Corporation, 11270 West Park Place, P. O. Box 24500, Milwaukee, WI 53224 USA, Tel: 855.424.9892
• Also see WATER SOFTENER PLUMBING PROBLEMS where we warn about crimped tubing or leaky tubing between the brine tank and the water softener control head or resin tank, causing weak brine flow due to crimps, blockages, or air leaks.