RESIDENTIAL GAS AND ELECTRIC WATER HEATER
SERVICE HANDBOOK
A.O. Smith Water Products Company Training Department
©2002 Ashland City, Tennessee
28
Residential Electric – continued
Cold tank of water
• Single Electrical Service
• Single Phase
A-7 Circuit
Post 1995
Fused Disconnect
Power to Upper High Limit 1,
and Upper Thermostat 3
Upper High Limit 1, 2 is Closed.
Upper Thermostat 3, 4 is Open
Upper Thermostat 1, 2 is Closed
Upper Element is On
No Power
to Lower
High Limit
Terminal 1
Top 1/3 of Tank is Heated
Upper Thermostat 1, 2 Opens
Upper Thermostat 3, 4 Closes
Power Flows Between
Upper Thermostat 4 and
Lower High Limit L1
Lower High Limit L1 and
Lower Thermostat T2 is Closed
Power to Upper High Limit 3
and Lower High Limit L3
Upper High Limit 3, 4 is Closed
Lower High Limit L3, L4 is Closed
Lower Element Heats Bottom 2/3 of Tank
