JennAir Over-the-Range Microwave E21 / E22 Thermal Sensor Code

Open versus shorted

The two codes differ by one word. Per JennAir’s over-the-range microwave page, E21 has the Thermal Sensor circuit telling the control board it is open, and E22 has it telling the board it is shorted.

Terms explained

• Thermal sensor: a temperature-sensing part.
• Circuit: the electrical link running between that sensor and the control board.
• Open: the link is interrupted somewhere.
• Shorted: the link touches something it should not.

These are everyday meanings of the words; the location of the break or short on this microwave is not given by JennAir.

Parts JennAir lists

Both codes share one list: the Thermal Sensor, the Appliance Control Board and the wiring. The source does not put the three in any order of likelihood.

What you can do

1. Turn the breaker off and keep it off for one minute.
2. Turn the breaker on.
3. Monitor for a minute to confirm E21 or E22 stays off the display.
4. Verify that the microwave operates.

Code still there

In the manufacturer’s phrasing, qualified assistance may be needed. Testing a sensor circuit requires measurements inside the microwave, which makes a returning E21 or E22 a technician’s task.

Short Q and A

Do E21 and E22 need different resets?
No. Suspects and reset are the same; only open versus shorted differs.

Does the code tell me the failed part?
It does not. The sensor, board and wiring are listed together.

Related sensor codes

• E61, E62 and E63: comparable open and shorted terms, applied to the oven sensor circuit
• E24: overheating, another entry listing the thermal sensor

Thermal sensor service in Los Angeles

To book in Los Angeles, call (310) 622-9465 and say whether E21 or E22 was shown. Bring up the model number as well. Details of microwave service are online.

Source: JennAir Product Help, Over-the-Range Microwave Error Codes