Maytag Washer Error Code F18

The Maytag F18 error code on a washer typically indicates a problem with the machine’s temperature sensing or heating circuit — most commonly a fault with the water temperature sensor (NTC thermistor) or its related wiring and controls. When the washer can’t read or regulate water temperature correctly, the control board may halt or modify cycles to protect the appliance and your laundry. You may notice incomplete cycles, unusually long wash times, incorrect temperature selection (water not getting hot or staying cold), or the washer stopping with an error displayed. In some cases, poor temperature regulation can lead to less effective cleaning, residue build-up on fabrics, and (rarely) a potential risk if a shorted circuit creates excessive heat. Identifying the exact cause early helps avoid repeated cycle interruptions and potential damage to the main control board or heater assembly.

Common causes

• Failed or out-of-spec temperature sensor (NTC thermistor).
• Broken, corroded or disconnected wiring/connectors between the sensor and control board.
• Faulty main control board or electronic control module.
• Defective heating element (if model uses a heater) or related relay not switching.
• Blown thermal fuse or safety thermostat interrupting the circuit.
• Moisture intrusion in the console or control area causing intermittent faults.
• Software/firmware glitch that may be resolved by a power reset.

Troubleshooting steps

1. Safety first: Unplug the washer or switch off its circuit breaker before inspecting components. Water and electricity are hazardous.
2. Power-cycle the washer: Leave it unplugged for 1–5 minutes and restore power. Sometimes the code clears if it was a transient error.
3. Run diagnostics: If your model supports a service/diagnostic mode, run the built-in test to confirm the F18 and any additional codes that narrow the cause.
4. Inspect visible wiring and connectors: Check harnesses around the front panel, control board, and temperature sensor for damage, corrosion, or loose connectors.
5. Test the temperature sensor: Locate the NTC thermistor and use a multimeter to check its resistance at room temperature (compare with the tech sheet/service manual). An open circuit or wildly out-of-spec reading indicates a failed sensor.
6. Check heating element & thermal fuses: If your model heats water, verify the heater element and safety thermostats for continuity. A failed heater or blown thermal fuse can trigger temperature-related errors.
7. Swap or bypass carefully: If you have a known-good sensor or connector, briefly swap to confirm the fault — only if you are experienced and the appliance is de-energized.
8. Inspect control board: Look for burned components, cracked solder joints, or signs of moisture on the main board. Replace the board if diagnostics and visual inspection point to control failure.
9. Clear the code and test: After any repair, clear the error (power cycle or use diagnostic mode) and run a full cycle to ensure the F18 does not return.
10. When in doubt, call a professional: If troubleshooting identifies control-board-level failures or if electrical testing is beyond your comfort zone, contact an authorized Maytag technician to avoid damage or injury.

Maintenance / Prevention Tips

• Keep the washer area dry and well-ventilated to prevent moisture reaching electronics.
• Regularly inspect visible wiring and connectors for signs of wear or corrosion.
• Run a manufacturer-recommended clean cycle monthly to reduce residue and blockages.
• Avoid overloading the washer — excess load can stress components and cause repeated cycles.
• Use the correct detergent and dosing to prevent buildup that can affect sensors.
• Level the washer properly to reduce vibration that can loosen wires or connectors.
• Keep the control console free of spills and moisture; wipe up detergent or water promptly.
• Schedule periodic professional service if you use the washer heavily (multi-family households, laundromat-style use).
• Replace suspect wiring harnesses at the first sign of chafing or exposed conductors.
• When replacing parts, use OEM or approved replacement parts to ensure correct sensor specifications.
• Document error occurrences (frequency/time/cycle) to help a technician diagnose intermittent faults.
• Use surge protection where possible — electrical spikes can damage control electronics.
• Keep the washer’s service manual or model-specific troubleshooting guide handy for reference.

FAQs

Conclusion / Safety Notice

Addressing an F18 code promptly helps prevent repeated cycle failures and protects the washer’s electronics and heating components. While some basic checks (power-cycling, visual inspections) are safe for most users, electrical testing and board-level repairs should be left to trained service technicians. If you suspect a failed control board, a shorted heater, or if you are uncomfortable performing electrical diagnostics, contact an authorized Maytag service provider to avoid risk of injury or further damage to the appliance.