Bosch Temperature Sensor Open Circuit

Furnace shows F2; may indicate sensor open circuit

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Broken sensor lead, Unplugged sensor connector, Corroded terminals, Damaged harness

Safety: Isolate power.

Check plug: Ensure the sensor connector is fully seated on the control board.
Continuity test: Measure resistance across the sensor. Infinite resistance indicates an open sensor; replace it.
Harness check: Wiggle the cable while measuring to detect intermittent breaks.

Medium 3/5

Temperature Sensor (NTC)

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