Softener or resin tank emits a constant hissing or whistling sound during normal service
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Hissing may indicate high-velocity flow. Do not disassemble the valve under pressure.
Step-by-step:
- Check bypass position: Ensure the AquaUnique bypass is fully in SERVICE and not partially between positions.
- Listen at drain: Check if water is trickling from the drain line during service. If so, the valve may be leaking internally.
- Regenerate: Run a full regeneration to flush debris that may be holding a seal open.
When to call a technician: Persistent hissing with drain flow usually requires replacement of the seal and spacer kit or the entire control valve.
Repair Difficulty
Required Part
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