Bonding

What is Bonding?

Bonding and grounding are related but distinct. Grounding establishes a reference to earth; bonding ties metal parts — water piping, gas piping, the metal frame of a structure, and equipment enclosures — together so that a fault cannot leave one metal surface energised relative to another. In practice inspectors look for a bonding jumper at the water service, continuity across the water heater (since dielectric unions can interrupt the path), bonding of the gas piping system, and bonding of pool and spa equipment where present, which has its own detailed requirements. Missing bonding is a common finding in older homes and in homes where a plastic section has been spliced into previously continuous metal piping.