THE WATER HEATER(S) SHALL BE RHEEM HEAVY DUTY ELECTRIC MODEL No. 616315 WITH AN HOURLY INPUT OF (6 x 3.6 kW.) OR (6 x 4.8 kW.) OR (6 x 6.0 kW.) AND A HOURLY RECOVERY RATE OF 372 (6 x 3.6 kW.) OR 495 (6 x 4.8 kW.) OR 619 (6 x 6.0 kW.) LITRES THROUGH 50°C RISE. THE WATER HEATER(S) SHALL CONFORM TO AUSTRALIAN STANDARD 1056. THE WATER HEATERS SHALL BE FACTORY ASSEMBLED AND TESTED. MODELS SHALL BE MANUFACTURED WITH IMMERSION ELECTRIC HEATING UNITS FITTED WITH SURFACE MOUNTED THERMOSTAT INCORPORATING A SAFETY OVER TEMPERATURE ENERGY CUT OUT.