A.O. Smith BTR 151 THRU 201/A warranty Service, Ignition Module System, Electrical Servicing

7.Lower container, you may have to place the container on its empty carton to prevent the UN•LIME from flowing back into the container.

8.Let UN•LIME remain in the heater for 5 minutes and then lower the container to the "Drain" Position, see Figure 15.

9.Deliming activity is indicated by foaming on the surface of the UN•LIME. If there is deliming activity, repeat steps 6 thru 8.

Normally, lime removal will be completed within one hour. Severe build-up of lime may take longer than an hour to complete descaling.

Note: To check UN•LIME for continued use, place some scale or white chalk in a glass with a small amount of UN•LIME. If the material is vigorously dissolved by the UN•LIME, it can be reused; if not, the UN•LIME should be replaced.

FIGURE 15

the appliance. The indicator codes on the ignition module are as follows:

1 flash	System lockout (retries or cycles exceeded)
2 flashes	Pressure switch stuck close
3 flashes	Pressure switch stuck open
4 flashes	Open on high temperature limit switch (eco)
6 flashes	115 volt AC power reversed (check polarity)
7 flashes	Low flame sense signal (make sure flame
	sensor is in burner flame)
8 flashes	Check ignitor

continuous flash -> continuous flame sensed > 5 seconds without gas valve

continuous on -> internal control failure - replace ignition control module.

Use this diagnostic system in conjunction with the “OPERATIONAL CHECKLIST” and the “SEQUENCE OF OPERATION” to troubleshoot the appliance.

SERVICE

The installer may be able to observe and correct certain problems which may arise when the unit is put into operation. HOWEVER, it is recommended that only qualified servicemen, using appropriate test equipment, be allowed to service the heater.

As preliminary step, check wiring against diagram, check for grounded, broken or loose wires. Check all wire ends to be sure that they are making good contact.

IGNITION MODULE SYSTEM

Before calling your service agent, the following checklist should be examined to eliminate obvious problems from those requiring replacement or servicing.

—Check that “main manual gas shutoff valve” is fully open and that gas service has not been interrupted.

—Check that after following the appliance OPERATING INSTRUCTIONS, the “Top Knob” of the appliance gas valve is in “ON” position.

—Check electrical supply to the appliance for possible blown (or tripped) fusing or power interruption.

—Is the water temperature in tank below the thermostat dial setting on the appliance thermostat (calling for heat)?

—It is possible that the high limit (E.C.O.) has functioned to shut off the appliance. See FEATURES — Water Temperature Control for reset procedure. Contact your serviceman if limit continues to function to shut off appliance.

ELECTRICAL SERVICING

CAUTION

LABEL ALL WIRES PRIOR TO DISCONNECTION WHEN SERVICING CONTROLS. WIRING ERRORS CAN CAUSE IMPROPERAND DANGEROUS OPERATION.

VERIFY PROPER OPERATION AFTER SERVICING.

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 the A.O. Smith Water Products Company, Product Service Division, 5621 West 115th Street, Alsip, IL 60803, 1-800-433-2545. When ordering parts be sure to state the quantity, part number and description of the item(s) including the complete model and serial number as it appears on the product. Refer to the parts list for more information.

SYSTEM DIAGNOSTICS

Your water heater is equipped with an ignition module that
incorporates a diagnostic system to assist in troubleshooting	REPLACEMENT PARTS

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