A.O. Smith GAHH-40 Control Display Troubleshooting, Control Display Status Problem Solution

Page 30

CONTROL DISPLAY TROUBLESHOOTING

ELECTRONIC CONTROL DISPLAY

Please check guidelines below. For your safety, water heater service should be performed only by a qualified service person.

Read the GENERAL SAFETY INFORMATION supplied by the water heater manufacturer.

 

CONTROL DISPLAY STATUS

PROBLEM

 

SOLUTION

 

 

 

 

 

1.

“POWER” Flashing

 

1.

Check the 5-conductor data cable that

Communication Error

 

runs between the upper and lower

 

 

The system has detected a

 

controls. Check that the wiring is not

 

 

 

broken, and the connectors on both ends

 

 

communication error between the

 

 

 

 

are properly seated in the mating

 

 

upper and lower controls.

 

 

 

 

connectors.

 

 

 

 

 

 

 

2.

Replace the upper control, if the problem

 

 

 

 

persists:

 

 

 

3.

Replace the lower control.

2.

“HEATING” and “SHORT” Flashing

 

1.

Turn the power off for 10 to 20 seconds

The self-diagnostic tests have

 

then on again to clear the error code.

 

 

found a problem with an internal

2.

If the error code persists or cannot be

 

 

circuit.

 

 

 

cleared, replace the lower control.

 

 

 

 

3.

“HEATING” and “OPEN” Flashing

 

1.

Gas supply is turned off – pressure too

Ignition/flame failure.

 

low. Ensure supply and manifold gas

 

 

The water heater has reached the

 

pressures are within requirements in the

 

 

 

installation manual. Manifold gas

 

 

maximum number of retries and is

 

 

 

 

pressure is non-adjustable, if pressure is

 

 

currently locked out for one hour.

 

 

 

 

off by more than 0.3” W.C. (75 Pa)

 

 

 

 

 

 

Cycle the power to the water

 

replace the lower control.

 

 

heater off and on to reset.

2.

Low supply voltage – should be 115 –

 

 

 

 

 

 

 

125 VAC.

 

 

 

3.

Ensure flame sensor is making good

 

 

 

 

contact with the burner flame, ensure

 

 

 

 

flame is steady.

 

 

 

4.

Ensure the flame sensor is clean – use

 

 

 

 

ultra fine steel wool or Scotch-BriteTMpad

 

 

 

 

to clean the flame sensor.

 

 

 

5.

Ensure the hot surface ignitor is

 

 

 

 

positioned to provide consistent ignition.

 

 

 

6.

Check for any cracks in the ignitor

 

 

 

 

assembly ceramic insulators – replace

 

 

 

 

ignitor assembly if damaged.

 

 

 

7.

Check resistance of the ignitor at room

 

 

 

 

temperature (77°F – 25°C) at the plug

 

 

 

 

end. Replace ignitor if the resistance is

 

 

 

 

not within 1.38 to 2.31 ohms at room

 

 

 

 

temperature.

4.

“HEATING”, “OPEN”, and “SHORT” Flashing

 

1.

Ensure flame sensor is making good

Weak flame sensor current.

 

contact with the burner flame, ensure

 

 

 

 

flame is steady.

 

 

 

2.

Ensure the flame sensor is clean – use

 

 

 

 

ultra fine steel wool or Scotch-BriteTMpad

 

 

 

 

to clean the flame sensor.

5.

“ECO” and “OPEN” Flashing

 

1.

Turn the power off for 10 – 20 seconds

Water temperature in the tank has

 

then on again to clear this error code.

 

 

exceeded 185°F (85°C) and has

2.

Replace the lower control if the error

 

 

activated the ECO.

 

 

 

code persists.

 

 

 

 

30

Image 30
Contents Residential GAS Water Heaters Table of Contents Safe INSTALLATION, USE and Service Safety PrecautionsFire or Explosion Hazard Typical Installation GET to Know Your Water Heater GAS ModelsImportant Information About This Water Heater Installing Your GAS Water HeaterUnpacking the Water Heater Excessive Weight Hazard Consumer InformationLocation Requirements Site LocationCarbon Monoxide Poisoning Hazard Clearances and Accessibility State of CaliforniaGas Requirements Gas Pressure TestingGAS Supply Gas PipingGas Pipe Capacity Table Confined Space Combustion AIR & VentilationUnconfined Space Minimum Btuh InputAll Air from Inside the Building All Air from OutdoorsLouvers and Grilles Draft Hood Installation Vent Pipe SystemChimney Connection Vent ConnectorsVent Pipe Size Vertical Exhaust Gas VentPiping Installation Water System PipingTemperature and Pressure Relief Valve Closed System/Thermal ExpansionCombination Space Heating/Potable Water System Temperature & Pressure Relief ValveRelief Valve and Pipe Insulation Discharge LineSolar Installation Wiring DiagramElectrical Connections Installation Checklist Important Information about this Water HeaterOperating Your Water Heater Operating InstructionsWater Heater Operation Checking the DraftBurn Hazard Water Temperature Regulation Burner FlamesEmergency Shut Down Condensation Safety Shut-offOperational Conditions Water Heater SoundsRoutine Preventive Maintenance Powered Anode OperationDraining and Flushing Removing the Manifold/Burner Assembly Maintenance of Your Water HeaterReplacement Parts Removing the Burner from the Manifold/ Burner AssemblyReplacing the Flame Sense/Hot Surface igniter Assembly Cleaning the Combustion Chamber and Air Diverter AssemblyReplacing the Manifold/Burner Assembly Removing and Replacing the Gas Control Valve/Thermostat Removing the Gas Control Valve/ThermostatReplacing the Gas Valve Pressurized Combustion Chamber System Operational Checklist Troubleshooting ChartCont Control Display Troubleshooting Control Display Status Problem SolutionControl Display Status Problem Solution FV-SENSE and Open Flashing Troubleshooting Flowchart YESRepair Parts List Repair Parts IllustrationListed Parts Kits and Illustrations Page Page Page Limited Residential GAS Warranty YearImportant Information