Summary
This blog identifies one possible cause of repetitive fan noise in the Bosch HBG633BS1A oven.
Operating Noise
After completion of an oven cleaning cycle, performed at 200°C, subsequent operation of the oven resulted in a repetitive buzzing noise. The noise occurred when the oven was powered from cold. This audio clip contains an example of the generated noise.
Rear Heating Coil Mounting
The rear fan appeared to be associated with the noise heard on power-up. With the oven unpowered, the four Torx T20 screws retaining the rear panel were removed. Detaching the rear panel exposed the fan and rear heater element.
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| Bosch Oven HBG633BS1A Internal Rear Plate |
The metal clip which provided space between the element and the rear chassis of the oven was misshaped causing it to contact the fan blade.
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| Bosch Oven HBG633BS1A Internal Rear Element Clip |
To resolve the clearance issue between the fan and the heater element, the shape of the clip was hand adjusted.
Manual rotation of the fan blades was performed to correct ensure clearance. The rear panel was fitted and no subsequent noises were noted.
