Water Heater Operation (24 Volt Only); System Error Codes For 24 Volt Controls - A.O. Smith ATMOSPHERIC VENTED WATER HEATER Installation And Operating Instructions Manual

Water Heater Operation (24 Volt only)

Thermostat calls for heat
Within 15 seconds:
•
Vent damper rotates to open position
•
Vent damper opening is confirmed and an electrical
signal is sent to the ignition system in the controller
Within 30 seconds:
•
Ignition system is powered and
•
Lights the pilot
•
Confirms pilot ignition
•
Allows the main valve to open
•
Burner ignites
At the end of the "On Cycle":
•
The thermostat contacts open
•
The ignition system closes the gas valve
•
Burner shuts "off"
•
The vent damper starts to close
Within 30 seconds:
•
The vent damper is fully closed

System Error Codes for 24 Volt Controls

The micro-controller inside the gas control monitors the
TCO safety feature, the ignition sequence, temperature set-
tings and overall operation of the heater. If any of these
parameters does not operate properly the controller will shut
down the water heater, diagnose the failure and flash an
error code. Table 3 lists the system status Codes for the 24
Volt Honeywell control.
Note: If a random power outage is experienced, your water
heater may experience a soft lockout for approximately 2
minutes. This lockout is required to allow the control to reset
itself.
If the gas control valve is submerged under water for any
length of time, the gas control valve assembly should be
replaced.
LED FLASH SEQUENCE
Short flash once
every four seconds
"Heartbeat", alternates
bright/dim
One Flash,
three second pause
Two Flash,
three second pause
Three Flash,
three second pause
Four Flash,
three second pause
Five Flash,
three second pause
Six-One Flash,
three second pause
Six-Two Flash,
three second pause
Six-Three Flash,
three second pause
Six-Four Flash,
three second pause
Seven Flash,
three second pause
Eight-One Flash,
three second pause
Eight-Two Flash,
three second pause
Eight-Three Flash,
three second pause
Eight-Four Flash,
three second pause
Table 3 Status Codes (Honeywell)
– 21 –
CONTROL STATUS
IDLE (no call for heat,
no fault conditions)
Call For Heat
(no fault conditions)
Low Flame Signal
(control continues to operate)
End Switch Failed Closed
TCO or End Switch Failed Open
ECO Limit Lockout
Flame Out Of Sequence
Soft Lockout - Retry Limit -
Failed TFI
Soft Lockout - Recycle Limit -
PS/Limit opened
Soft Lockout - Recycle Limit -
Flame Lost
Soft Lockout - Flame out of
Sequence Sensed
Flammable Vapor Sensor
Lockout
FVS Fault Detected
Temperature Sensor Fault
Detected
Electronics Fault Detected
Valve Fault Detected