HUB Parts › Water Heater PTF Coupling Image 1 of 3 Image 2 of 3 Image 3 of 3 Water Heater PTF Coupling $11.00 Quantity: Add To Cart Added! This fitting is installed on the water heater. Includes replacement rubber o-ring.Quick connect design enables an easy connection to the faucet. This fitting is installed on the water heater. Includes replacement rubber o-ring.Quick connect design enables an easy connection to the faucet.