RESIDENTIAL GAS AND ELECTRIC WATER HEATER
SERVICE HANDBOOK
A.O. Smith Water Products Company Training Department
©2002 Ashland City, Tennessee
37
Residential Electric – continued
A-6 service Voltage Check “No Hot Water” – continued
Test between Thermostat 2 and High Limit 4 or T2 and L4
If … … then
supply voltage is present: continue.
supply voltage is not present • check jumper between high limit 2 and
thermostat 1.
• replace thermostat – (tank must be 15°F
cooler than setting to activate thermostat.
Complaint: Lack of Hot Water
Conditions:
Upper thermostat satisfied
Lower portion of tank still calling for heat
Test between high limit 4 and thermostat 4 and L4 and T4
If … … then
correct supply voltage is present continue.
correct supply voltage is not present • check that tank water temp has satisfied
the upper thermostat.
• replace the upper thermostat.
Test between high limit 4 and lower thermostat 1 or L4 and 1
If … … then
correct supply voltage is present continue.
correct supply voltage is not present check wiring connections.
Test between high limit 4 and lower thermostat 2 or L4 and 2
If … … then
correct supply voltage is present continue.
correct supply voltage is not present replace lower thermostat.
