HBL5750UC/08 Bosch Wall Oven. Broiler element comes on / stays on in all cook modes.

pfbzzz

Premium Member
Joined
Jul 10, 2017
Messages
11
Location
us
Model Number
HBL5750UC/08
Brand
Bosch
Age
6-10 years
Bosch wall oven, microwave combo, HBL5750UC/08

Problem:
  • In any cook mode but off, broiler element comes on and stays on. This used to happen intermittently, now all the time.
  • Eventually the over-temp sensor will trigger and turn it off.
  • Turning oven to "off" will turn off broiler element.

  • Built-in diagnostics (from downloaded service manual) don't show any relevant faults.
  • Temp readings from sensors (again, using built-in diagnostics) seem accurate.
  • Using diagnostics to turn on broil element turns it on, but again, will never turn off.

All of this leads me to believe it is a stuck relay?

Question:

I've seen references to a "control/relay board" and a "relay board". I suspect one of these components.

Control/Relay board comes up as Bosch part #12022212. This board looks like it has many small relays on it.

Relay board comes up as Bosch part #00663802. This looks more like a power supply board than a relay board.

Should I replace the relay board?


bosch control board.jpg

relay board.jpg
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
103,413
Location
McMullen Valley, Arizona
Hi,

Control/Relay board comes up as Bosch part #12022212. This board looks like it has many small relays on it.
That's the main relay board you would need, that one controls the heating elements.

You can order it here:
Control Module 12022212


Jake
 
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