Thermador Oven Fan Won’t Turn Off – How to fix? by HoustonAuthorizedRepair.com
The part(s) or condition(s) listed below for the symptom Oven fan won’t turn off are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
Most Frequent Causes for Oven Fan Won’t Turn Off
| Cause 1 Oven Control Board | Cause 2 High Limit Thermostat | Cause 3 Thermostat |
| The oven control board has relays that regulate power to the bake, broil and fan circuits according to the user settings and sensor input. If one of these relays shorts out, the control board may send continuous voltage to the oven fan. However, this is rarely the case. Before replacing the control board, first check the oven thermostats. If an oven thermostat fails, it may cause the oven fan to run continuously. | The high limit thermostat sends voltage to the oven fan as the oven heats up. If the high limit thermostat is defective, it may keep sending voltage to the oven fan after the oven has cooled down. To determine if the high limit thermostat is at fault, use a multimeter to test the thermostat for continuity. If the high limit thermostat does not have continuity, replace it. | The thermostat sends voltage to the oven fan as the oven heats up. If the thermostat contacts are stuck closed, the thermostat may continue to send voltage to the oven fan after the oven has cooled down. To determine if the thermostat is at fault, use a multimeter to test the thermostat for continuity. If the thermostat shows continuity at any temperature, this indicates that the thermostat is defective. If the thermostat is defective, replace it. |
