Clack WS1 Error Codes: What 101, 102, 103, 104, 106 and 107 Mean
Sep 30, 2026The short version: a Clack WS1 shows an error code when the motor can’t move the piston where it expects to. The common ones are 101 (can’t find the start of regeneration), 102 (unexpected stall), 103 and 104 (motor ran too long reaching the next cycle or home), and 106 or 107 (a problem with the second valve used on some systems). A power reset sometimes clears it. If the code comes back, something is binding inside the valve and it needs a technician.
The codes, from the Clack service manual
| Code | Manual description | What it usually means |
|---|---|---|
| 101 / 1001 / E1 | Unable to recognize start of regeneration | The control can’t confirm the piston position. Often a loose connection, a motor issue, or after the valve was opened |
| 102 / 1002 / E2 | Unexpected stall | Something is binding the piston, often debris or worn seals in the spacer stack |
| 103 / 1003 / E3 | Motor ran too long, timed out trying to reach next cycle position | The piston isn’t reaching position. Drive, gear or piston problem |
| 104 / 1004 | Motor ran too long, timed out trying to reach home position | Same family as 103, on the way back to service. Drive bracket alignment is a common cause |
| 106 / 1006 | MAV/NHWB unable to find proper park position, motor ran too long | A problem with the auxiliary valve (MAV or no-hard-water-bypass) used on some systems, or a programming mismatch |
| 107 / 1007 | MAV/NHWB motor ran too short (stalled) looking for park position | Something is jamming the auxiliary valve |
Descriptions from Clack’s WS1 & WS1.25 Drawings and Service Manual.
What you can do yourself
- Write down the code and take a photo of the display.
- Check the power. Make sure the adapter is plugged in and the outlet works. GFCI outlets in garages trip often.
- Reset it. Unplug the valve for about 30 seconds and plug it back in. The manual lists a reset as a first step for several codes.
- Put it in bypass if hard or no water. Turning the bypass knobs sends untreated water to the house while you wait for service.
Don’t force the piston or open the valve while it’s under pressure. If the code returns after a reset, the cause is mechanical and opening it without the right parts usually makes it worse.
When to call a technician
Call if the code comes back after a reset, if you see water running to the drain nonstop, or if the softener stopped using salt. On these valves the fix is usually a piston, seal and spacer kit, a motor, or a drive bracket that isn’t seated. Those are standard Clack parts, which is one reason we build on this valve.
Problems that don’t show a code
- The time is flashing. The power was out longer than the battery carries the clock (about 8 hours). Your program is saved in memory; just reset the time of day.
- Salt isn’t going down. Check for a salt bridge first. Then a clogged injector or brine line. See water in the brine tank.
- Hard water but no code. Out of salt, the bypass left open, or the hardness setting is wrong. See still hard water after a softener.
- Water running to drain during the day. It may be mid-regeneration, or it may be stuck. See softener draining during the day.
Common questions
What does error 101 mean on a Clack valve?
The Clack manual describes 101 (also 1001 or E1) as “unable to recognize start of regeneration.” The control can’t confirm the piston position. Try a power reset; if it returns, have the motor and connections checked.
What does error 102 mean on a Clack WS1?
An unexpected stall. Something is binding the piston, often debris or worn seals in the spacer stack. It usually needs a technician.
How do I reset a Clack WS1 error?
Unplug the valve for about 30 seconds and plug it back in. If the error returns, the cause is mechanical and needs service.
Why is the time flashing on my Clack softener?
The power was out longer than the backup battery carries the clock, about 8 hours. The program is saved; reset the time of day.
Can I still use water with a Clack error code?
Yes. Put the softener in bypass and the house gets untreated water until it’s repaired.
Do you repair Clack valves?
Yes. Our own techs repair Clack valves across Manatee and Sarasota counties, usually with a standard piston, seal and spacer kit or a motor.
Error code won’t clear? Text us a photo of the display at 941-266-8991 and we’ll tell you what it likely needs.
Related: Softener repair, any brand · Softener not working? · Water in the brine tank · Clack WS1 review · Clack models explained
Sources: Clack Corporation, Water Specialist WS1 & WS1.25 Drawings and Service Manual (troubleshooting section) and WS1 specifications.
