I've had small surges when turning on the microwave before. We thought the microwave was going out. We replaced it with a larger and older model we had in storage. I turned on the replacement microwave and a surge went through the line, catching fire to a surge protector in one room and blowing the circuit in two others. could of been bad. Its not the microwave apparently and didn't throw a circuit breaker. What could be causing this. I haven't changed anything on the circuit for over a year at least. This all happened in the last month, the big surge came today; sure makes for a smelly house.