Tip of the iceberg? New HVAC field reports strengthen ACCA’s GFCI appeal

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Contractor experiences in Colorado and Massachusetts raise questions about the extent of unwanted GFCI tripping nationwide.

On October 22, ACCA submitted supplemental information to the National Fire Protection Association (NFPA) in support of its appeal seeking additional time to resolve compatibility concerns associated with Section 210.8(F) of the National Electrical Code (NEC). The appeal concerns the September 1, 2026, expiration of Exception No. 2, which temporarily exempted certain outdoor HVAC equipment from GFCI protection requirements.

ACCA supports electrical safety but maintains that unresolved equipment compatibility issues, inconsistent enforcement practices, and the lack of comprehensive field performance data warrant additional time before the requirements are broadly enforced.

New reports from the field

Recent contractor reports from Colorado and Massachusetts illustrate the challenges that continue to confront HVAC contractors and their customers.

In Colorado, an electrical contractor reported unwanted GFCI tripping involving multiple heat pump installations in the Boulder area. The reported incidents involved equipment from different manufacturers and GFCI breakers from several manufacturers. Some installations experienced repeated trips that interrupted heating service.

The contractor reported approximately $1,300 in direct expenses associated with troubleshooting and corrective work, excluding administrative time. The incidents also raised concerns about loss of heating during winter conditions, potential frozen pipes, and customer confidence.

In Massachusetts, an electrician reported repeated GFCI tripping associated with a heat pump installation in the MetroWest area. Replacing the GFCI breaker did not resolve the reported problem, leaving the contractor seeking an acceptable solution.

Although these reports do not conclusively establish the cause of every trip, they demonstrate the practical difficulties contractors continue to encounter.

Minnesota takes a different approach

Minnesota’s implementation of Section 210.8(F) provides another important perspective.

The state has limited enforcement to new construction, exempting replacement installations in existing residences. This approach avoids imposing the new requirements on homeowners replacing existing HVAC equipment.

Minnesota also lacks a centralized reporting system for unwanted GFCI trips in new construction, making it difficult to determine the extent of potential compatibility problems.

The differences between Minnesota’s approach and enforcement practices in other jurisdictions highlight the uncertainty facing contractors operating across state lines. To read more about Minnesota go to the following link: Minnesota Turns on HVAC GFCI Protection: What Are We Learning?

An issue that has persisted for years

ACCA’s supplemental filing also revisits technical concerns identified during earlier NFPA deliberations, including leakage currents associated with electronically commutated fan motors and other HVAC components.

These concerns are not limited to inverter-driven compressors. Equipment compatibility may be difficult to predict based solely on model identification or equipment labeling.

Although newer high-frequency GFCI devices have entered the market, their availability does not, by itself, establish compatibility with every HVAC equipment configuration.

ACCA seeks additional time

ACCA and the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) have appealed NFPA’s rejection of a proposed extension of Exception No. 2 to September 1, 2028.

The additional time would allow manufacturers, contractors, and other stakeholders to continue evaluating equipment compatibility, gathering field performance information, and developing workable solutions.

NFPA’s Standards Council is scheduled to consider the appeals in conjunction with its December 15 – 16, 2026 meeting.

ACCA will continue working with industry partners and encouraging contractors to document unwanted GFCI tripping incidents, including equipment models, breaker manufacturers, troubleshooting efforts, and associated costs.

The question is no longer whether unwanted GFCI tripping is occurring. The question is how much of the iceberg remains beneath the surface.

For additional information and updates, visit ACCA’s GFCI Resource Page at  Outdoor HVAC GFCI Requirements & State Guidance | ACCA – ACCA .  For questions please contact ACCA’s manager of codes david.bixby@acca.org.

 

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Posted In: Electrical, Field Safety, Safety, Workplace Safety