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HomeRepair HelpThermador Microwave RepairThermador Microwave is tripping circuit breaker Repair
Thermador Microwave is tripping circuit breaker
When your Thermador microwave is tripping the circuit breaker, especially when the door opens or closes, the most likely cause is a failed door switch. Most models use three or four switches, including the primary door switch, secondary door switch, and monitor switch, which must operate in sequence. A defective switch can short the circuit, blow the line fuse, or trip the breaker. The next possibility is a shorted high-voltage capacitor, followed by a shorted magnetron or high-voltage transformer. A failed transformer may also arc or produce a burnt smell. Testing these parts with a multimeter requires electrical knowledge, and any repair that involves opening the outer cabinet requires extreme caution. The high-voltage capacitor can store a lethal charge even after the microwave is unplugged, so it must be properly discharged before interior work. If you are not familiar with capacitor discharge procedures, have a qualified technician handle the repair. Enter your Thermador microwave model number to find the exact replacement door switch, high-voltage capacitor, magnetron, or transformer for your specific appliance.
01 - Thermador Microwave Door Switch
Most microwaves have three or four door switches. When the microwave door closes, the door switches actuate in sequence to ensure that the door is closed properly. If any of the door switches fail, the microwave line fuse can blow, or the circuit breaker may trip. To determine if any of the door switches are defective, use a multimeter to test each of the switches for continuity. If any of the door switches lack continuity, replace the defective switch. (Caution: The microwave oven can store thousands of volts of electricity in its high voltage capacitor, even after the microwave oven has been unplugged. Due to the potenti...
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02 - Thermador Microwave High Voltage Capacitor
A microwave that is tripping a circuit breaker can be caused by a shorted high voltage capacitor. You can determine that a capacitor has shorted by contacting one multimeter lead to one of the capacitor's terminals and the other lead to the casing. If meter display indicates that electrical continuity is present between any of the capacitor terminals and the casing, or the terminals show continuous continuity between them, the component has shorted and will need to be replaced.
Uncommon But Possible
03 - Thermador Microwave Magnetron
A microwave that is tripping a circuit breaker can be caused by a shorted magnetron. You can determine that a magnetron has shorted by contacting one multimeter lead to one of the magnetron's terminals and the other lead to the casing. If meter display indicates that electrical continuity is present between any of the terminals and the casing, the magnetron has shorted and will need to be replaced.
Uncommon But Possible
04 - Thermador Microwave High Voltage Transformer
A microwave that is tripping a circuit breaker can be caused by a shorted high voltage transformer. When a high voltage transformer shorts out, it will usually arc and smell burnt.
Uncommon But Possible
Frequently Asked Questions
Why is my Thermador microwave tripping the circuit breaker?
Why does my microwave trip the breaker when the door opens or closes?
Can a high-voltage capacitor or magnetron cause a Thermador microwave to trip the breaker?
What should I check before replacing the magnetron in a microwave that keeps tripping the breaker?
How do I find the correct Thermador microwave replacement part?
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