Lennox Heat Pump Error Code DS2:AlternatingSlowFlash / DS1:AlternatingSlowFlash

This alternating slow flash pattern on both DS1 and DS2 LEDs indicates the heat pump is in a 5-minute anti-short cycle delay. The control board enforces this timed hold after initial power-up, a safety device trip, or at the end of a thermostat demand cycle. It is a protective function designed to prevent compressor damage and is not a fault code.

Yes, the alternating slow flash indicates a normal protective delay, not a dangerous fault. The unit is simply waiting out a timer before restarting. You do not need to shut down the system or call for emergency service based on this status alone. However, if the system trips into this delay repeatedly in a short period, a technician should evaluate the safety controls.

If the delay itself is the only issue, there is no repair cost. If the delay is being triggered by a recurring safety fault, repair costs depend on the root cause and could range from around $100 to $600 or more depending on whether refrigerant service, a pressure switch replacement, or coil cleaning is needed. A technician diagnostic visit is typically required to identify the specific safety device involved.

In most cases, no fix is needed. The system will automatically resume normal operation once the 5-minute timer expires. If you are a technician performing diagnostics and need to bypass the delay, you can jumper the TEST pins on the control board to override the timer. If the delay is recurring frequently, inspect for an underlying safety trip condition.

Resetting power to the unit will not skip the delay and will actually restart the 5-minute timer from the beginning, since power-up is one of the triggers for this hold. The most effective way to clear the delay during a service call is to use the TEST pin jumper on the control board. Under normal operation, simply waiting out the 5-minute period is the appropriate response.