Symbio 700 did not include R454B refrigerant until v7 firmware released in November 2024. R454B units started shipping in January 2025 with v7.01.0014. When replacing a newer Symbio 700 with a replacement board from parts or a truck stock, that board will need to have it's firmware updated to allow newer features to be set in the unit configuration. It is always recommended to update to the latest available firmware.
For instructions on updating Symbio 700 firmware, see this link: Symbio™ 700 - Firmware Update for Unit Controller Module
Out-of-date firmware can also be tied to other missing configuration issues:
- Heat pump on 3-10T Precedent missing from configuration on Symbio 700 (new feature for v7)
- Modulating Hot Gas Reheat is missing from the configuration on Symbio 700 (new feature in v4)
- Ultra High Efficiency or Eflex is missing from cthe onfiguration on Symbio 700 (new feature added in v4)