Denso Air Conditioner Error Code PU

The PU code means the drain pan float switch has detected continuously high water levels in the condensate pan for 60 seconds, triggering the condensation overflow protection. The unit's internal drain pump is not moving water out of the pan quickly enough, which causes water to build up and activate the shutoff. This is a protective fault designed to prevent water damage to the unit and your property.

No, you should not continue operating the unit while the PU code is active. The unit has shut down specifically to prevent condensate from overflowing, which could cause water damage to ceilings, walls, or floors, and potentially create electrical hazards. Leave the unit off until the drainage issue is identified and corrected.

If the issue is simply a kinked or clogged drain hose, repairs may cost little to nothing beyond your time. Professional cleaning of the drain pan and pump area typically ranges from around $75 to $200 depending on labor rates in your area. If the internal drain pump itself needs replacement, parts and labor combined can range from approximately $150 to $400 or more depending on the unit and service provider.

Start by inspecting the drain hose for any kinks, sharp bends, or blockages along its entire length and clear or straighten as needed. Next, check the drain pan itself for accumulated slime or debris that may be clogging the pump inlet, and clean it out thoroughly. If the hose and pan are clear but the error persists, the internal drain pump may need testing or replacement. After resolving the underlying issue, power cycle the unit to clear the fault.

A power reset may temporarily clear the PU fault display, but the code will return if the underlying drainage problem has not been resolved. The float switch will detect high water levels again once the pan refills and the 60-second timer elapses. Clearing the fault code without fixing the root cause is not a solution and risks water overflow damage.