System Diagnosis
Control Board Failure / Voltage Issue. The control board is not functioning properly or voltage is out of range.
Lennox | LED Status Codes (DS1 & DS2)
Error Code Alt Fast Flash / Alt Fast Flash
Troubleshooting guide for the Lennox LED Status Codes (DS1 & DS2) system fault Alt Fast Flash / Alt Fast Flash.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
Potential Causes & Solutions
- Bad control board, voltage spike/drop.
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