The Winterhalter GS 302 is a professional-grade dishwasher known for reliability, but like any appliance, it can occasionally encounter issues. One such problem is when the machine heats the boiler to the correct temperature (e.g. 85°C) but fails to transfer water to the main wash chamber. This guide outlines common causes and diagnostic steps to help identify and potentially resolve this issue.
🔧 Symptoms Overview
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Machine powers on normally.
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Boiler heats up to ~85°C.
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Water does not fill the wash tank.
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Water does not circulate or initiate a wash cycle.
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Constant 65 V AC present at the wash pump, regardless of control panel state.
1. 🔍 Step-by-Step Diagnosis
✅ Step 1: Check the Wash Pump Voltage
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Measure the AC voltage on the wash pump terminals.
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A reading of ~65 V (instead of ~230 V) in all states may indicate:
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Triac fault on the control board
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Incorrect neutral or ground connection
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Partially failed relay
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💡 Note: The motor may receive residual voltage due to faulty switching, but not enough to activate.
✅ Step 2: Verify Water Supply
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Ensure incoming water pressure is adequate.
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Check that the water inlet valve is opening.
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Clean any inlet filters or strainers that might be clogged.
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Inspect for limescale or sediment that may be blocking flow.
✅ Step 3: Float Switch / Water Level Sensors
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Inside the machine, the float switch or water level sensor may be:
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Jammed due to debris or grease
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Disconnected
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Faulty (causing the controller to believe the tank is already full)
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🔧 Remove and clean the float area thoroughly.
✅ Step 4: Check the Drain Pump (if present)
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If the drain pump is stuck in an active state, water will continuously drain and not fill the chamber.
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Ensure:
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Drain pump is not jammed.
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Drain hose isn’t siphoning out water.
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No level sensor is falsely detecting overfill.
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✅ Step 5: Examine the Control Board
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Constant 65 V on the pump might suggest:
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Malfunctioning triac or relay (responsible for switching power to the pump).
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Damaged PCB traces or burned components.
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Water ingress or oxidation on the mainboard.
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⚠️ If you’re not trained in electronics, consult a technician for PCB diagnostics and repair.
✅ Step 6: Manual Test Mode (If Supported)
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Many Winterhalter machines have a test or diagnostic mode (accessed by key combinations on the control panel).
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In test mode, manually activate:
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Inlet valve
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Wash pump
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Heating elements
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Drain pump
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This can help isolate the failed component.
2. 🔌 Safety Reminder
Always disconnect the dishwasher from mains power before working on internal components. Working with residual voltage or faulty wiring poses serious electrical risks.
3. 🔁 Summary of Common Causes
| Symptom | Possible Cause | Recommended Action |
|---|---|---|
| Boiler heats, but no wash cycle starts | Float switch jammed or failed | Clean or replace float switch |
| Low constant voltage on pump (65 V) | Faulty triac or relay on PCB | Inspect/repair/replace mainboard |
| No water in tank | Inlet valve failure or blocked filter | Clean filter, test valve |
| Water drains immediately | Stuck drain pump or siphoning | Check drain valve and routing |
4. 🔧 When to Call a Technician
If none of the above steps resolve the issue, or if internal board repairs are required, it’s advisable to contact an authorized Winterhalter service technician. They can run full diagnostics using service tools and ensure safe repair.
✅ Final Tip
To prevent future issues:
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Descale the machine regularly (especially in hard water areas).
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Keep filters and floats clean.
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Have the machine serviced annually in a professional setting.