A.O. Smith BTN 120 THRU 400/A Series Replacement Parts, Service Handbooks And Training Aids

REPLACEMENT PARTS, SERVICE HANDBOOKS AND TRAINING AIDS

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.

REPLACEMENT PARTS

SEQUENCE OF OPERATION FLOW CHART

Description of this flow chart can be found in the “SEQUENCE OF OPERATION” section found on page 23.

Switch power on	Ignition
	Control Board
to unit.	opens Gas
	Valve.
	Ignition Control
	Board shuts off
Thermostat calls	Silicon Nitride
for heat.	Ignitor after
	3 seconds
Ignition Control	Ignition Control
Board performs	Board waits 3 more
diagnostic check on	seconds to
components	monitor Flame
	Sensor.
Ignition Control
Board sends power
to Exhaust Inducer			Ignition Control
	Did Main
		NO	Board shuts off Gas
	Burner Light?		Valve and allows the
			Exhaust Inducer to
Exhaust Inducer			purge appliance for
			20 seconds.
engages Prover
Switch
	YES
Ignition Control
Board provides	Ignition Control
power to Silcon	Board monitors
Nitride Ignitor	units until T’Stat
	is satisfied.
Silicon Nitride
Ignitor
warms up for
20 seconds
	30