HVAC Heater Molded Hose (19202) by Gates®. Location: Heater to Water Pump. Inside Diameter: 0.72″. Inside Diameter 2: 0.62″. Gates molded heater molded hose is manufactured to fit specific applications. Similar to OEM specifications. Gates recommends replacing standard worm drive and spring loaded clamps with Gates PowerGrip(R) SB Clamps each time a new coolant hose is installed.