Troubleshooting Guidelines - A.O. Smith GPVX 75L Series Installation And Operating Manual

These guidelines should be utilized by a qualified service agent.
PROBLEM
BURNER FLAME
TOO HIGH
FLAME BURNS
AT ORIFICE
INSUFFICIENT
HOT WATER
WATER IS TOO HOT
SLOW HOT WATER
RECOVERY
DRIP FROM
RELIEF VALVE
GAS CONTROL VALVE/
THERMOSTAT FAILS TO
SHUT OFF
44

TROUBLESHOOTING GUIDELINES

POSSIBLE CAUSE(S)
1. Air inlets blocked
2. Insufficient secondary air
3. Orifice too large
1. Low gas pressure
2. Defective gas control valve/thermostat
1. Low gas pressure
2. Orifice too small
3. Thermostat set too low
4. Gas control error codes
5. Sediment or lime in tank
6. Water heater too small
7. Wrong piping connections
8. Leaking faucets
9. Wasted hot water
10. Long runs of exposed piping
11. Hot-water piping in outside wall
1. Thermostat is too high
2. Incorrect or missing vent screen in vent
termination
3. Defective gas control valve/thermostat
1. Insufficient air/flue blockage
2. Low gas pressure
3. Orifice too small
4. Thermostat set too low
5. Heater too small
6. Wrong piping connection
7. Wasted hot water
8. Flue clogged
9. Air inlets blocked
1. Pressure build-up
2. Heater stacking
3. Closed water system
4. Improperly seated valve
5. Water overheating
1. Defective gas control valve/thermostat
CORRECTIVE ACTION
1. Unblock inlet air openings
2. Provide ventilation to water heater
3. Replace with correct orifice
1. Check with gas utility company
2. Replace gas control valve/thermostat
1. Check with gas utility company
2. Replace with correct orifice (see rating
plate)
3. Turn temperature knob to higher
setting
4. Refer to gas control error codes
5. Drain/flush-provide water treatment if
needed
6. Install adequate heater
7. Correct piping: dip tube must be in cold
inlet
8. Repair faucets
9. Advise customer
10. Insulate piping
11. Insulate piping
1. Turn temperature knob to lower setting
2. Check venting for correct screen
3. Replace the gas control valve/
thermostat
1. Provide ventilation to water heater.
Check flue way, flue baffle and burner
2. Check with gas utility company
3. Replace with correct orifice (see rating
plate)
4. Turn temperature knob to higher
setting
5. Install adequate heater
6. Correct piping-dip tube must be in cold
inlet
7. Advise customer
8. Clean flue, locate source and correct
9. Unblock inlet air openings
1. Use a pressure-reducing valve and
relief valve
2. Lower the thermostat setting
3. See "Thermal Expansion" section
4. Check Relief valve for proper operation
(Do Not plug T&P valve)
5. Check venting for proper vent
termination screen. Check valves in
loop system stuck or missing.
1. Replace gas control valve/thermostat
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