P6 Error Code – Low Pressure Protection

Short answer: P6 means the system's refrigerant pressure has dropped too low, so the unit has stopped to protect the compressor. It usually means the system is low on refrigerant, often from a leak. This is not a DIY repair: a licensed HVAC technician needs to find and fix the cause.

What you can do

1. Switch the unit off at the breaker for at least 30 minutes, then back on. If P6 does not come back, keep an eye on it.
2. If P6 returns, stop using the unit and book a licensed HVAC technician. If your system was installed recently, call the installer first.
3. Submit a support ticket with a photo of the display, the model/serial label (where to find it), and your installation date. Repairs on a professionally installed system may be covered under warranty.

For technicians

Quick test: set the unit to heating at the maximum temperature and run it for 15 minutes. The larger pipe leaving the outdoor unit should be very hot (around 105°F / 40°C). If it is not, the system is likely low on refrigerant.

Typical pressures: about 400 psi in heating mode and about 100 psi in cooling mode.

Check flare connections and service valves for leaks, repair, pressure test, evacuate and recharge to the nameplate charge. For R-454B systems, see the R-454B Pressure Level Chart. Tech+ support can walk you through tests at 1-800-242-4935, option 3.