What F3T4 Means
F3T4 is published as a possible problem with the magnetron temperature thermistor or the associated wiring. The magnetron is the component that generates the microwave energy, and it has its own temperature sensor because it must not be allowed to run hot.
Common Causes of F3T4
- Vents obstructed, so the magnetron runs hot
- Cooling fan failing
- Thermistor connector loose
- Magnetron thermistor failed
- Magnetron genuinely overheating
🔧 One Safe Check You Can Try
Switch the microwave off at its circuit breaker for one minute, restore power, then run a short heating test with a cup of water to verify operation, which is the check Maytag asks for. Then check that nothing is obstructing the vents around the microwave, since the magnetron is cooled by that airflow and a restricted vent produces genuine heat rather than a false reading. If the code returns, stop using the microwave for heating until it is diagnosed. A magnetron temperature fault is not one to work around, because the sensor exists precisely to protect an expensive and high-energy component.
⚠ Why You Shouldn't Go Further Than That
- A microwave oven holds a high voltage capacitor that can retain a dangerous charge long after the appliance is unplugged, so the cabinet is never opened at home under any circumstances.
- An over-the-range unit is mounted above a cooking surface at head height and is heavy enough to need two people and a support to remove safely.
- The magnetron sits next to the high voltage circuit, which is the most dangerous part of any microwave oven.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.