The Hubbell water heater is constructed with a heat trap installed within the water heater’s hot water outlet connection. This device helps prevent heat from escaping through the storage tank’s hot water outlet during standby periods, resulting in improved operating efficiency. The heat trap is constructed from a specially designed bronze nipple with an internal floating ball that during standby periods of no flow settles and closes off the storage tank thereby preventing thermal conduction of hot water radiating through the hot water outlet.