Why Is My Water Softener Making Noise? What Each Sound Means

Is It Normal for a Water Softener to Make Noise?

Yes, some noise is normal, but only at the right time. A softener is close to silent while it's softening your water. It gets noisy when it regenerates, the cycle where it flushes the resin and recharges it with salt brine. During that cycle you'll hear a motor whir and click as the valve changes position, water rushing down the drain line, and a quiet hiss or trickle at the brine tank. The control starts the cycle at a programmed time of day, normally in the middle of the night, so many owners never hear it.

What's not normal is noise that doesn't fit that pattern: water running to the drain for hours, a motor that keeps starting and stopping, grinding from the control head, or salt that never goes down. The table below sorts the common sounds, and the sections after it explain each one.

What a Normal Regeneration Sounds Like

To know which sounds belong, it helps to know what the softener is doing. Crystal Quest® whole-house softeners use a Vtrol control head, which is a Fleck 5600 valve. Its 5600 SXT service manual lists the valve positions in order for a standard single-backwash softener, and each position has its own sound:

Between those steps you'll hear the drive motor. The manual's startup procedure tells the installer to "allow the drive motor to move the piston" to each regeneration step and to let the motor stop before moving on, so a few seconds of whirring followed by a click, repeated at each step change, is exactly what a healthy valve sounds like.

The rushing water is also expected, and there's a fair amount of it. Penn State Extension's water softening guide estimates that "about 50 gallons of water are used for each regeneration cycle." If your softener sits next to a laundry sink or floor drain, that's a lot of water to hear going by, and it's fine.

Hearing It at an Odd Hour?

A regeneration in the middle of the afternoon doesn't always mean something's wrong. Four things can shift the timing:

• A manual regeneration. Holding the Extra Cycle button for five seconds starts one right away, so someone in the house may have pressed it.
• A power outage. If power fails mid-regeneration, the manual says the valve stays where it is until power returns, then the control resumes the cycle from that point. You might hear the rest of a cycle at an odd hour after the lights come back on.
• A long outage. The control keeps track of the time on its backup for at least 48 hours, and the time of day flashes after any outage. If the power was off longer than that and nobody reset the clock, the regeneration you set for the middle of the night can land at a very different real time.
• A metered control set to regenerate right away. A meter immediate control starts a regeneration as soon as the softener's capacity is used up, whatever the hour.

Sounds That Point to a Problem

These are the sounds worth acting on. The causes below come from the troubleshooting table in the same Vtrol service manual, so they apply directly to Crystal Quest softeners and to most other Fleck 5600 valves.

Water Running to the Drain Nonstop

A regeneration ends. If you hear water running down the drain line for hours, or every time you walk past, the valve is probably stuck in a regeneration position or leaking inside. The manual's causes for "drain flows continuously" are a valve that isn't positioning correctly, foreign material inside the control, and an internal leak that calls for new seals and a new piston assembly. That's a slow, constant waste of water, so don't leave it running for days.

Clicking or a Motor That Keeps Cycling

A few clicks per regeneration are normal. A motor that keeps starting, or a control that clicks through positions over and over, isn't. The manual lists "control cycles continuously" with one cause: a misadjusted, broken or shorted switch, fixed by replacing the switch, the timer or the whole power head.

Grinding, Straining or an Error Code

A motor that grinds, labors or hums without the valve moving usually means something in the drive or the piston is binding. The control watches for this. On the Vtrol control, error code 0 means the valve drive took longer than six minutes to reach the next position. The manual's recovery steps are to unplug the unit, check that the motor, drive train and switches are in good shape and that the piston moves freely, then plug it back in. If the error comes back, it says to unplug the unit and contact technical support.

Hissing at the Brine Tank, but the Salt Never Goes Down

A hiss during the brine step is the softener pulling brine. If the salt level stays the same week after week and your water is turning hard, the softener isn't actually drawing brine. Before blaming the valve, look for a salt bridge, a hard crust that leaves a hollow space over the water. Our water softener troubleshooting guide shows how to find and break one. If there's no bridge, the manual's causes for "softener fails to draw brine" are a plugged drain line flow control, a plugged injector or injector screen, an internal leak, and water pressure that's too low. It calls for at least 20 psi of line pressure.

Banging in the Pipes

A single knock in the plumbing when the valve changes position comes from water stopping or changing direction quickly in the pipes, often called water hammer. It isn't the softener failing, but it's hard on fittings. If it's loud or rattles the pipes, have a plumber look at how the lines are supported.

Gurgling or Sputtering After Plumbing Work

Gurgling, spitting faucets or a sputtering drain line right after an installation, a repair or a resin change is usually air in the system. The startup instructions in the manual have the installer open a cold water tap and let it run "until the air is purged from the unit." Doing the same thing after any service usually clears it.

What You Can Check Yourself

Most of the diagnosis takes five minutes and no tools:

1. Read the display

   Note whether it shows normal service or a regeneration step, whether an error code is showing, and whether the time is flashing, which means the power went out.

2. Match the sound to the clock

   Compare when you hear it with the regeneration time set on the control. Noise at that hour, ending within the cycle, is normal.

3. Look in the brine tank

   Check the salt level and push gently on the salt with a broom handle to find a bridge. Our softener salt guide covers which salt is least likely to cause one.

4. Check the drain line

   Make sure the drain hose isn't kinked, crushed or frozen, since a restricted drain shows up in several of the manual's fault causes.

5. Bypass it if water won't stop

   If water runs to the drain nonstop or the unit is leaking, put it in bypass so the house keeps water while you arrange a repair. Our bypass valve guide shows how for each valve type.

If the noise is coming from a reverse osmosis system under the sink rather than the softener, the causes are different. Our guide to reverse osmosis noises covers those. And if you'd like to understand the regeneration cycle itself in more depth, start with how water softeners work.