Boiler

Related terms

• Bonding (Pools/Gas/Water)

  Tying metallic systems together so they can't carry a dangerous voltage difference. Specific bonding is required for gas piping, water li…

• Blower Door Test

  A fan-and-gauge test measuring whole-house air leakage. Code increasingly requires a passing result after major remodels.

• Box Fill

  The NEC limit on how many conductors/devices fit in an electrical box. Overfilled boxes overheat and are a common inspection failure.

• Backwater Valve

  A check valve in the building drain preventing municipal sewer backups from flooding the home. A recommended add in basement remodels.

• Branch Circuit

  Wiring from a breaker to the outlets/devices it serves. Circuit count and dedicated circuits are core to any kitchen, bath, or addition.

• Backflow Preventer

  A device stopping contaminated water from being siphoned back into the potable supply. Code-required at hose bibs, irrigation, and boilers.

• Building Drain / Sewer Lateral

  The main drain leaving the house to the city sewer or septic. Aging clay/cast laterals are a major hidden-cost risk in older homes.

• Backdrafting

  Combustion gases (including CO) being pulled back into the house instead of up the flue, often from negative pressure caused by exhaust f…