Lennox Heat Pump Error Code DS2 Alternating SLOW Flash / DS1 Alternating SLOW Flash

This LED pattern means the heat pump control board is counting through a 5-minute anti-short cycle delay. The delay is triggered by one of three conditions: initial power-up, a safety circuit trip, or the end of a thermostat demand cycle. The compressor will not run during this window. The system will resume automatically once the timer completes.

Yes, this condition is safe and is actually a protective function designed to prevent compressor damage. The unit is simply waiting out a timed delay before allowing the compressor to restart. No components are at risk during this period, and the system will return to normal operation automatically.

If the delay is recurring due to repeated safety trips, diagnostic costs typically range from $75 to $150 for a service call. Repair costs depend heavily on the root cause: refrigerant recharge services generally range from $150 to $400, while component replacements such as a pressure switch or blower motor can range from $100 to $600 or more depending on parts and labor. If the compressor itself has been damaged by repeated short cycling, replacement costs are significantly higher.

In most cases, no fix is needed. Simply wait for the 5-minute timer to expire and the system will restart on its own. If you are a technician needing to bypass the delay for diagnostic purposes, shorting the TEST pins on the control board will override the timer. If the condition is occurring repeatedly due to safety trips, the root cause of those trips must be identified and corrected.

Cycling power will not skip the delay and will actually restart the 5-minute anti-short cycle timer from the beginning, since initial power-up is one of the three triggers for this condition. The most effective way to bypass the delay for testing purposes is to use the TEST pin jumper on the control board, which overrides the timer immediately.