F8
Giant
Sensor Configuration / Type Mismatch
F8 error and control indicates sensor mismatch or configuration error
Advertisements
Safety Warning
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.
Advertisements
Possible Causes
Incorrect replacement sensor installed, Mixed thermistor types on same control, Wrong control board model for heater, Damaged sensor harness
How to Fix / Troubleshooting
Safety first: Disconnect power before working on sensors or control wiring.
- Verify part numbers: Check that all temperature sensors installed are genuine Giant parts with the correct part numbers for your model.
- Inspect harness: Ensure that inlet, outlet, and tank sensors are connected to the correct labeled terminals on the control board.
- Check for mixed sensors: Do not mix NTC thermistors of different values. If any sensor was replaced with a non‑Giant part, replace it with the correct Giant sensor.
- Control compatibility: Confirm that the electronic control board is the correct replacement for your specific Giant water heater model.
- Reset and test: After correcting any mismatches, reset the control and verify that F8 clears.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Giant Temperature Sensor Set
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements