A.O. Smith GPDH, Owner'S Manual

Page: 17 / 20

17
TROUBLE SHOOTING
Please check guidelines below. For your safety, water heater service should be performed only by a qualified service technician.
Read the GENERAL SAFETY INFORMATION section first.
PROBLEM SOLUTION
An open earth ground circuit to the 1. Check that the earth ground connection is
ignition system. properly connected.
2. Check that the ground conductor on the
water heater is properly connected.
Wiring error or a high resistance to 1. Check for proper connection of line
earth ground. neutral and hot wires.
2. Check that the water heater is securely
connected to earth ground.
Pressure switch remained closed longer 1. Pressure switch wiring is incorrect.
than 5 seconds after the call for 2. Replace pressure switch.
heat began.
Pressure switch remained open longer 1. Pressure switch wiring is incorrect.
than 5 seconds after the combustion 2. Pressure switch tubing not connected
blower was energized. correctly.
3. Air intake or exhaust obstructed.
Error in the hot surface igniter circuit. 1. Check that all wiring is correct and secure.
2. Replace hot surface igniter.
System in lockout. 1. Gas supply is off or too low to operate.
2. Hot surface igniter not positioned
correctly.
3. Low voltage to the water heater.
4. Electric polarity to unit is incorrect - test
and correct.
Problem in the gas valve driver circuit. 1. Turn power to the water heater off for
10 seconds and the back on.
2. Replace gas control valve.
Problem with the internal circuit. 1. Turn power to the water heater off for
10 seconds and then back on.
2. Replace gas control valve.
Problem with the internal circuit. 1. Turn power to the water heater off for
10 seconds and then back on.
2. Replace gas control valve.
Flame signal sensed out of 1. Replace gas control valve.
proper sequence.
ECO activated. 1. Replace gas control valve.
One of the temperature adjust 1. Press and release each of the buttons
buttons stuck closed. once.
2. Replace gas control valve.
Water temperature sensor is 1. Check that all wiring is correct and secure.
either open or short circuited. 2. Replace gas control valve.
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
A B C
LED STATUS
W
A
TER HEA
TER CONTROL
WARNING: DO NOT BY-PASS ANY CONTROLS TO MAKE HEATER OPERATE.
OPERATE ONLY AS WIRED FROM FACTORY.