National Electrical Code Mandates GFCI Protection for All 240V HVAC Units as Exemption Expires

Contractors installing new heat pumps this week warn that mandatory electrical upgrades will leave homeowners sweltering when sensitive breakers trip over harmless baseline current. Safety regulators and code officials counter that those same breakers are the only barrier preventing a degraded compressor from electrifying a metal chassis and killing a technician or a child playing in the yard. The grace period separating those two positions ended on September 1.[3][4]

The National Electrical Code (NEC) now requires Ground-Fault Circuit Interrupter (GFCI) protection for all outdoor 240-volt HVAC equipment. The rule originally appeared in the 2020 code cycle, but widespread industry pushback forced a series of delays and temporary exceptions. As of last Tuesday, the final extension expired in jurisdictions enforcing the latest code, meaning any new central air conditioner or heat pump installation must include a GFCI breaker at the panel.[1][6]

The friction stems from how modern, high-efficiency climate control actually operates. Variable-speed inverter drives—the technology that allows modern heat pumps to sip electricity rather than blasting on and off—naturally leak a tiny amount of electrical current to the ground wire during normal operation. A standard GFCI breaker is designed to trip and cut power if it detects a leak as small as 4 to 6 milliamps.[2][5]

For a homeowner, this creates a frustrating dynamic. A brand-new, $10,000 heat pump might run perfectly but still trigger the GFCI breaker on a hot afternoon, shutting down the house's cooling. HVAC technicians refer to this as "nuisance tripping." Because the system itself is not actually malfunctioning, resetting the breaker restores power, but the homeowner is left paying for a service call just to be told the safety switch is too sensitive for the equipment.[4][7]

Trade groups, including the Air Conditioning Contractors of America (ACCA) and the Air-Conditioning, Heating, and Refrigeration Institute (AHRI), petitioned aggressively to extend the exemption. They argued that manufacturers need more time to redesign inverter drives to leak less current, or that breaker manufacturers need to develop HVAC-specific GFCIs with higher trip thresholds. Those petitions failed to secure a nationwide delay before the September deadline.[3][4]

Because building codes are adopted locally, the expiration creates a fragmented map for buyers. States like Texas and Virginia, which rapidly adopt updated NEC standards, are enforcing the mandate immediately. In those markets, electrical inspectors will fail new HVAC installations that lack the required GFCI protection, forcing contractors to factor the $150 to $300 breaker upgrade into their initial bids.[5][7]

Code panels maintain that the upgrade is non-negotiable for residential safety. Outdoor condenser units sit in the rain and snow, vibrating heavily for years. When wire insulation degrades and touches the metal casing, the entire unit becomes electrified. Without a GFCI, the first person to touch the cabinet—often a technician performing summer maintenance—completes the circuit to the ground, risking fatal electrocution.[1][2]

Buyers scheduling installations this fall must navigate the new reality. Installers are advising homeowners to locate their main electrical panels and learn how to identify a tripped GFCI breaker, hoping to minimize emergency weekend service calls. Equipment manufacturers are accelerating software updates for their inverter drives to smooth out the electrical signatures that confuse the breakers, while contractors adjust their pricing to cover the mandatory electrical work.[6][8]