EXP Tankless Water Heater Service Valves are the preferred choice for isolating any tankless water heater. These valves provide quicker consistent quality installations, with fewer leakpaths and simplify future maintenance. Designed for use with water, oil, glycol mix in residential or commercial residential plumbing, commericial plumbing, heating systems. Refer to specification sheets for additional technical information. All Webstone products are backed by a limited lifetime warranty.