What E21 or E22 Means
These two codes describe the same circuit failing in opposite directions. Maytag states that E21 means the thermal sensor circuit reported open to the control board, and E22 that it reported a short. Both name the thermal sensor, the appliance control board, or the associated wiring as possible causes.
Common Causes of E21 or E22
- Transient fault cleared by a reset
- Sensor connector loose or corroded
- Sensor wiring chafed or heat-damaged
- Thermal sensor failed open or shorted
- Appliance control board fault
🔧 One Safe Check You Can Try
Switch the microwave off at its circuit breaker for one minute, restore power, and then run a short heating test with a cup of water to verify operation, which is the check Maytag asks for. Then test the microwave function with a cup of water and note whether it heats normally. A thermal sensor circuit that reads open or shorted is an electrical test with a meter on a part inside the cabinet, so there is nothing further to try at home. What helps the technician is knowing which of the two codes appeared, since open and short point at different failure modes in the same circuit.
⚠ 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 also mounted above a cooking surface at head height and is heavy enough to need two people and a support to remove safely.
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.