- Appliances
- Water softeners
Error 1
Fleck Error 1 on water softener: cycle step input fault
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
High
Quick answer
Error 1 (shown as ---1 on the Fleck SXT screen) is a Cycle Step Error or Cycle sense error triggered when the controller receives an unexpected cycle input. Unplug the unit, plug it back in, and if ---1 returns, unplug it and contact a water treatment professional.
Safety first
Stop and check this first
- Do not attempt to open the controller or repair internal switches yourself: the Fleck SXT Owner's Manual states there are no user-serviceable parts in the AC adapter, motor or controller.
- Do not change the Valve Type (VT) or Regenerant Flow (RF) settings in Master Programming without verifying the internal valve subcomponents first.
Safe checks you can perform
- Unplug the softener and plug it back in
- Check whether Master Programming was recently changed
- Set the bypass valve to Bypass if the unit is unplugged mid-cycle
Leave these tasks to a qualified professional
- Do not attempt this professional task: Inspect powerhead cam switches and circuit board connections
- Do not attempt this professional task: Verify Valve Type in Master Programming and step through regeneration
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Inspect powerhead cam switches and circuit board connections
What they doThe technician unplugs the unit, opens the powerhead and verifies that all cam switches are firmly connected to the circuit board and actuating properly as the cam rotates.
They must show youthe cam switch wiring on the circuit board and the switches engaging cleanly against the cam.
In writingthe inspection result for each cam switch and any wiring or switch replacement carried out.
Verify Valve Type in Master Programming and step through regeneration
What they doThe professional enters Master Programming Mode (at 12:01 PM), verifies that Valve Type (VT) and system type match the physical unit, and steps the valve through a full manual regeneration using the Extra Cycle button.
They must show youthe verified VT and CT settings and the valve advancing cleanly through Backwash, Brine Draw, Rapid Rinse and Brine Fill back to In Service.
In writingthe Master Programming parameters checked and confirmation that manual regeneration completed without Error 1.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Unplug the softener and plug it back in
- Who:
- you.
- How:
- disconnect the AC power adapter from the wall outlet, wait a few seconds and plug it back in as instructed in Section 6 of the Fleck 5600 SXT User Guide for ---1. Observe whether the powerhead finds its home position and clears the code.
- Result that matters:
- the controller returning to the normal In Service screen without ---1.
- If the screen resumes normal operation:
- keep an eye on the next regeneration cycle.
- If Error 1 reappears on the display:
- unplug the unit as the service manual specifies and contact technical support.
- Evidence to keep:
- a photo of the ---1 display and a note of whether it appeared after a power cut or button press.
Evidence: FLECK 5600SXT Downflow Service Manual (42684 Rev L) · FLECK 5800 SXT Downflow/Upflow Service Manual (43359-01 Rev G) · User guide Fleck 5600 SXT (Ref. MKT-UG-013 / G)
Check whether Master Programming was recently changed
- Who:
- you, with your installation record or manual.
- How:
- check if anyone adjusted the controller while the clock was set to 12:01 PM, which unlocks Master Programming Mode (DF, VT, CT). Pentair cautions users to contact their local professional water dealer before entering Master Programming.
- Result that matters:
- knowing whether Valve Type (VT) or Control Type (CT) might have been altered accidentally.
- If settings were changed recently:
- let the technician know so they can check Master Programming against the valve hardware.
- If no settings were touched:
- the technician should focus on the cam switches inside the powerhead.
- Evidence to keep:
- your Original settings table or Job Specification Sheet showing the installer's setup.
Evidence: FLECK 5600SXT Downflow Service Manual (42684 Rev L) · FLECK 5800 SXT Downflow/Upflow Service Manual (43359-01 Rev G) · User guide Fleck 5600 SXT (Ref. MKT-UG-013 / G)
Set the bypass valve to Bypass if the unit is unplugged mid-cycle
- Who:
- you.
- How:
- if you unplug the unit because Error 1 keeps returning and the valve is not in the normal service position, turn the bypass valve behind the control head to BYPASS as illustrated in the Fleck SXT Owner's Manual.
- Result that matters:
- uninterrupted water supply to the house while the softener remains safely isolated and unplugged.
- If water flows normally in the home with the bypass engaged:
- leave it in Bypass until the service visit.
- If water tastes salty or feels hard:
- report that to local tech support as noted in Section 8 of the user guide.
- Evidence to keep:
- the model, part number and serial number from the serial label on the device.
Evidence: Fleck SXT Controllers Owner's Manual (44001 Rev E) · User guide Fleck 5600 SXT (Ref. MKT-UG-013 / G)
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Appliances
- Brand
- Fleck
- Product type
- Water softeners
Known code variants
- ---1
- Antes de comenzar asegúrese de que el sensor láser de distancia no esté bloqueado
- Asegúrese de que no haya blindaje en el sensor de alcance láser
- Código de error 1
- Collision bumper is stuck
- Cycle sense error
- Cycle Step Error
- El parachoques de colisión está atascado
- Err 1
- Error 1
- Error 1 bumper
- Error 1 laser
- Error 1 paragolpes
- Error 1 Roomba i Series
- Error Code 1
- Error de sentido de ciclo
- Error en el paso del ciclo
- Error1
- eufy bumper stuck
- eufy Error 1
- eufy RoboVac Error 1
- Fleck ---1
- Fleck 5600SXT Error 1
- Fleck Err 1
- Fleck Error 1
- Front bumper stuck
- iRobot Error 1
- Laser distance sensor
- LDS error
- Mi Robot Vacuum Error 1
- paragolpes frontal atascado
- Please make sure the laser distance sensor is not blocked before starting
- Please make sure there is no shielding on the laser ranging sensor
- Please toggle the laser head and check that there is no blockage or jamming
- Roborock Error 1
- RoboVac Error 1
- Roomba Error 1
- Rowenta bumper stuck
- Rowenta error 1
- Rowenta Error S1
- Rowenta Error W1
- Rowenta parachoques atascado
- Uneven ground
- X-plorer error 1
- X-plorer Serie 75 error 1
- Xiaomi Robot Vacuum Error 1
What it means
In the Pentair Fleck 5600 SXT User Guide (MKT-UG-013) and the Fleck 5600SXT and 5800 SXT Service Manuals (42684 and 43359-01), Error Code 1 (displayed as ---1 on the In Service display) is called a Cycle Step Error or Cycle sense error. It means the control experienced an unexpected cycle input from the cam switches. Other models may differ, and the code alone never proves that the circuit board, cam or microswitches have failed.
Warnings and stop conditions
- Highsource verified
Do not attempt to open the controller or repair internal switches yourself: the Fleck SXT Owner's Manual states there are no user-serviceable parts in the AC adapter, motor or controller.
Evidence: Fleck SXT Controllers Owner's Manual (44001 Rev E) · User guide Fleck 5600 SXT (Ref. MKT-UG-013 / G)
- Lowsource verified
Do not change the Valve Type (VT) or Regenerant Flow (RF) settings in Master Programming without verifying the internal valve subcomponents first.
Evidence: FLECK 5600SXT Downflow Service Manual (42684 Rev L) · FLECK 5800 SXT Downflow/Upflow Service Manual (43359-01 Rev G)
Symptoms and causes
Probable causes · in order
- Loose or misadjusted cam switch on the powerheadCommon
A cam microswitch that is loose, misadjusted or poorly connected to the circuit board sends an unexpected cycle signal to the SXT control.
Evidence: FLECK 5600SXT Downflow Service Manual (42684 Rev L) · FLECK 5800 SXT Downflow/Upflow Service Manual (43359-01 Rev G)
- Valve Type (VT) or system type mismatch in Master ProgrammingPossible
Pentair's service manuals state that Error 1 can occur if the Valve Type or System Type settings in Master Programming Mode do not match the physical unit.
Evidence: FLECK 5600SXT Downflow Service Manual (42684 Rev L) · FLECK 5800 SXT Downflow/Upflow Service Manual (43359-01 Rev G)
- Temporary cycle sync loss cleared by a power resetPossible
The Fleck 5600 SXT User Guide advises unplugging the unit and plugging it back in first, as a simple power cycle clears transient cycle sense faults.
Evidence: User guide Fleck 5600 SXT (Ref. MKT-UG-013 / G)
Virtual technician
Does Error 1 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
FLECK 5600SXT Downflow Service Manual (42684 Rev L)
Pentair · 2018 · official_doc
- 2
FLECK 5600SXT Flujo descendente Manual de servicio (42684-S Rev K)
Pentair · 2017 · official_doc
- 3
FLECK 5800 SXT Downflow/Upflow Service Manual (43359-01 Rev G)
Pentair · 2022 · official_doc
- 4
Fleck SXT Controllers Owner's Manual (44001 Rev E)
Pentair · 2022 · official_doc
- 5
User guide Fleck 5600 SXT (Ref. MKT-UG-013 / G)
Pentair · 2026 · official_doc
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