A.O. Smith 201, 200, 2500, 2100, 1850, 1300 Replacement Parts, Troubleshooting Ignition System, Led

CAUTION

IF HEAT EXCHANGER MAINTENANCE REQUIRES TUBING REPLACEMENT, SPECIAL PROVISIONS SHALL BE TAKEN TO ENSURE THAT THE DAMAGED TUBES ARE CAREFULLY REMOVED.

REPLACEMENT TUBES MUST BE PROPERLY INSTALLED AND EXPANDED INTO THE ROLLED TUBE TUB.

OVER-ROLLING, MISALIGNMENT OF TUBES OR IMPROPER TIGHTENING OF THE ASSEMBLY MAY RESULT IN LEAKS OR DAMAGE TO THE HEAT EXCHANGER. CONTACT YOUR A. O. SMITH DEALER FOR DETAILED INSTRUCTIONS.

REPLACEMENT PARTS

Replacement parts may be ordered through A. O. Smith dealers, authorized servicers or distributors. Refer to the Yellow Pages for where to call or contact (in United States) the A. O. Smith Water

Products Company, 5621 West 115th Street, Alsip, IL 60803, 1-800-433-2545 or (in Canada) A. O. Smith Enterprises Ltd., 768 Erie Street, Stratford, Ontario, Canada N5A 6T3, 519-271-5800. When ordering parts be sure to state the quantity, part number and description of the item including the complete model and serial number as it appears on the product. Refer to the parts lists for more information.

For Technical Assistance call A. O. Smith Technical Information Center at 1-800-527-1953.

TROUBLESHOOTING

Before any extensive troubleshooting, ensure that:

•Power (120 VAC) is supplied to the appliance.

•System control (tank probe, thermostat, etc.) is calling for appliance operation (call for heat).

•Other contacts (switches) are closed (low water cutoff, flow switch, limit controls, pressure switches, etc.)

•Gas supply pressure is within the maximum and minimum operating ranges listed on the appliance rating plate/label.

•Appliance is wired according to wiring diagram.

NOTE: Shorting the thermostat wiring to ground in the 24 volt circuit will blow the 3 amp fuse.

•All wire terminals/connectors are firmly attached to valves, modules, switches, limit controls, etc.

•There has been no damage caused by freezing, inoperative pumps, etc.

CAUTION

MAKE SURE POWER IS DISCONNECTED FROM MAIN BREAKER BEFORE SERVICING.

CAUTION

LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING CONTROLS. WIRING ERRORS CAN CAUSE IMPROPER FUNCTIONING OF UNIT RESULTING IN PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.

TROUBLESHOOTING IGNITION SYSTEM

The control system has several features to aid in troubleshooting problems which may occur during operation. If a fault occurs, the

33

Display Board contains sixteen (16) red fault LED indicators to help pinpoint the source of failures. In addition, the display will inform the user on which stage the failure occurred by illuminating a red Stage LED. In cases where the problem persists to lockout, the appropriate red LEDs will remain illuminated and a three digit error code will flash on the display screen. A summary of error codes is given in table 19. The error codes are broken into two categories: hard lockouts and soft lockout.

Hard Lockouts:

Hard lockouts require a manual reset accomplished by pressing the Enter/Reset push-button on the Display Board. Cycling the power "OFF" and "ON" will not reset the control.

Soft Lockouts:

Soft Lockouts also require a manual reset accomplished by pressing the Enter/Reset push-button on the display board. However, under a soft lockout condition, the control will re-initiate an ignition process after one (1) hour provided the call-for-heat is still present and will continue every hour until the unit is either reset or ignites.

A description of the red fault LEDs and their corresponding functions are as follows.

LED	Controller Function
Blocked Flue	Indicates a blockage or interference at the
	appliance flue.
Temp. Probe Fail	Indicates failure at one of the temperature
	probes. Unit will "lock-out" only if controlling
	probe fails.
Insufficient Air	Indicates air pressure was too low to create
	a sufficient differential to close the
	differential pressure switch.
Circulate Fail	Indicates water flow was too low to close
	the flow switch.
Gas Valve Fail	Monitors Gas Valve relay output. LED is ON
	when the output relay supplying power to
	the gas valve(s) is open.
High Limit	Monitors ECO in the Outlet Temperature
	probe. LED is ON when the ECO is open.
Flame Fail	Monitors the Flame Sense Rod. LED is ON
	when a signal from the flame rod is not
	sufficient to indicate flame.
Igniter Fail	Indicates igniter current was too low to meet
	minimum value which allows trial for
	ignition to continue.
Low Gas Fail	Inlet gas pressure is not sufficient to close
	gas pressure switch.
High Gas Fail*	Manifold gas pressure is has exceeded
	designed maximum value.
LWCO Fail*	Indicates water level in system is too low for
	safe operation.
Power Vent Fail*	Air pressure at Power Vent Switch is not
	sufficient for safe operation.

*Optional Equipment - LEDs will illuminate only if equipment is connected to boiler.

Upon lockout, manually push the ENTER/RESET button on the display panel to restart the boiler.

Verify proper operation after servicing.