The 73 error code indicates a circuit board setting issue. It is triggered by the following conditions:
- The maintenance writer on the circuit board is set incorrectly.
- The circuit board (microprocessor) is malfunctioning.
- The gas type setting and LP conversion connector are configured incorrectly.
Any changes made to jumper wires inside the unit should be done with the unit disconnected from power.
If you received a replacement circuit board please follow the directions included in the box to either transfer the programming data from the old board to the new one or manually program the new one. Otherwise directions can be found in the service manual for the unit you are working on.
This error code can be reset by unplugging the heater for 30 seconds and then plugging it back in.
For further technical assistance call 866-766-7489 or use our Contractor Locator to find a local service representative.