Display shows E04 and regeneration stops in mid-cycle with water left in brine tank

Safety first: Disconnect power. Close inlet and outlet valves and open a nearby tap to relieve pressure before removing the drain hose.

Step-by-step checks:

• 1. Inspect drain hose routing: Ensure the drain hose from the control valve to the waste connection is not kinked, crushed, or running uphill excessively. Straighten any tight bends.
• 2. Check for blockages: Disconnect the drain hose at the valve end. Blow through the hose or flush it with water to confirm it is clear. Remove any sludge or scale buildup.
• 3. Verify drain termination: Make sure the hose discharges into an open trapped gully or standpipe and is not submerged or sealed airtight, which can cause backpressure.
• 4. Clean drain flow restrictor: Many Scalemaster valves have a small restrictor orifice in the drain port. With the hose removed, inspect the port and gently clear any debris with a soft brush or toothpick. Do not enlarge the orifice.
• 5. Test regeneration: Reconnect the hose securely, restore water and power, and manually start a regeneration. Observe the drain flow during backwash and brine rinse stages. A strong, steady flow should be present.

If E04 recurs and drain flow is weak despite a clear hose, the internal valve seals or piston may be obstructed or worn and require professional service.