Led Diagnostic Codes - A.O. Smith 400 - 2100 Installation & Operation Manual

7
Operating information
Figure 7-9_LED Diagnostic Codes
Status LED Diagnostic Codes
Code
Sequence
Constant
System OK, no faults present.
ON
Possible control fault, check power; LED
Constant may be defective, do not replace control if
OFF all operational sequences function properly,
see Troubleshooting Guide.
Low Air, check air pressure switch and hoses
One to pressure sensing points, fan, venting and
Flash sealing of pressurized chamber. Note: Brief
fl ashing normal on fan start-up proving.
Flame without call for heat, check for a gas
Two valve stuck in the open position, air, venting,
Flashes burners and the combustion process. Fan
will remain on.
Lockout due to fl ame failure, push the
reset button on the diagnostic panel after
Three correcting ignition problem. Initial heater
Flashes start up without properly bleeding air from
the gas line may require multiple reset
functions to achieve proper ignition.
Igniter failure, igniter will not maintain a
Four minimum 2.75 amp current draw, caused
Flashes by low voltage, bad wiring/continuity, high
resistance or igniter failure.
Power supply problem, check for low supply
Five
voltage or transformer output less than 18
Flashes
VAC.
Six
Replace ignition module, internal fault.
Flashes
50
Condition
Installation & Operation Manual
Status LED Diagnostic Codes
Code
Condition Lights
Sequence
Operation for combustion air fan
Prepurge
before ignition on stages 1 and 2.
Trial for Hot surface igniter preparing to
Ignition light burners.
Stage 1
Burners for stage 1 operating.
ON
Stage 2
Burners for stage 2 operating.
ON
Remote status light for ignition
Status
module.
Indicates fl ame failure on the
ignition module and will indicate
Alarm
additional alarms if the alarm of any
failure option is purchased.