Display shows “Err 4” and the unit may not track water usage correctly (regenerates too often or not at all).

Safety first: Unplug the softener and place it in bypass before disassembling plumbing connections.

• Step 1 – Verify symptom: Check if the display shows water flow when no water is running, or shows zero flow when faucets are open. This confirms a flow sensing issue.
• Step 2 – Access turbine assembly: Shut off inlet water and relieve pressure. Remove the turbine housing (usually on the outlet side of the valve body). Note orientation for reassembly.
• Step 3 – Clean turbine: Remove the turbine wheel and rinse under running water. Clear any iron, sand, or debris from the blades and housing. Ensure the turbine spins freely with a gentle puff of air.
• Step 4 – Inspect sensor and wiring: Check the turbine sensor (Hall-effect or reed switch) for cracks or corrosion. Verify the sensor harness is firmly connected to the control board and not pinched.
• Step 5 – Replace faulty parts: If the turbine is damaged or the magnet is missing, replace the turbine assembly. If the sensor tests open or shorted, replace the turbine sensor. Reassemble, restore water, and test by running a faucet while watching the flow indication on the display.

Note: After repair, confirm that the softener counts down remaining capacity correctly over a day or two of normal use.