Hubbell ST - Manual (Page 17)

17
SHUTDOWN
1. Close valve to heating medium and air supply valve, if air operated controls are furnished
2. Disconnect all electrical power to unit.
3. Close hot water outlet valve.
4. Close building recirculation inlet valve, and shut down building circulation pump.
5. Close cold water inlet valve.
6. Turn off pump, if supplied.
7. Drain unit by lifting lever on relief valve to vent tank, then slowly open drain valve.