A.O. Smith GB/GW-200 warranty Troubleshooting Ignition System, Display Board LED Indicators, Led

Figure 2. WHC 1502 Ignition Control Board

DANGER

TANK PROBE JUMPER J33 IS ON AS DEFAULT, READY FOR USE WITH TANK PROBE SUPPLIED WITH THE BOILER (GW MODELS ONLY. SEE FIGURE 3 FOR CONNECTION DIAGRAM).

FOR STANDARD TANK CONTROLS (e.g., 24 VAC HONEYWELL AQUASTAT) REMOVE THIS JUMPER AND CONNECT THE CONTROL TO THE BROWN WIRES IN THE JUNCTION BOX ON THE BACK OF THE BOILER.

TROUBLESHOOTING IGNITION SYSTEM

Display Board LED Indicators

HOT WATER TEMPERATURES REQUIRED FOR AUTOMATIC DISHWASHER AND LAUNDRY USE CAN CAUSE SCALD BURNS RESULTING IN SERIOUS PERSONAL INJURY AND/ OR DEATH. THE TEMPERATURE AT WHICH INJURY OCCURS VARIES WITH THE PERSON'S AGE AND TIME OF EXPOSURE. THE SLOWER RESPONSE TIME OF DISABLED PERSONS INCREASES THE HAZARDS TO THEM. NEVER ALLOW SMALL CHILDREN TO USE A HOT WATER TAP, OR TO DRAW THEIR OWN BATH WATER. NEVER LEAVE A CHILD OR DISABLED PERSON UNATTENDED IN A BATHTUB OR SHOWER.

THE WATER HEATER SHOULD BE LOCATED IN AN AREA WHERE THE GENERAL PUBLIC DOES NOT HAVE ACCESS TO SET TEMPERATURES.

It is recommended that lower water temperatures be used to avoid the risk of scalding. It is further recommended, in all cases, that the water temperature be set for the lowest temperature which satisfies the user's hot water needs. This will also provide the most energy efficient operation of the water heater and minimize scale formation.

SETTING THE WATER HEATER TEMPERATURE AT 120°F WILL REDUCE THE RISK OF SCALDS. Some states require settings at specific lower temperatures. Table 1 below shows the approximate time-to-burn relationship for normal adult skin.

Table 1: Risk of Scalds
Temperature	Time to Produce 2nd & 3rd
Setting	Degree Burns on Adult Skin
Over 170°F	Nearly instantaneous
160°F	About 1/2 second
150°F	About 1-1/2 seconds
140°F	Less than 5 seconds
130°F	About 30 seconds
120°F or less	More than 5 minutes

The Display Board contains eleven (11) solid state LED indicators for viewing various states of appliance operation and for trouble- shooting if problems occur. Under normal operating conditions, the appropriate LED’s will sequence with steady illumination according to the particular appliance operating state. In cases where prob- lems or a lockout occurs, the appropriate LED’s will illuminate indi- cating the general area where the problem exists.

A description of the LED’s and their corresponding functions are as follows.

LED	Controller Function
Call for Heat	Monitors Outlet water temperature minus
	Switching Differential and thermostat circuit or
	tank probe circuit. LED is ON when the tem-
	perature at Outlet Water Probe is less than the
	set-point minus the switching differential, and the
	thermostat circuit or tank probe circuit is closed.
Flow Switch	Monitors the condition of the flow switch. LED
	is ON when the flow switch closes, indicating
	water flow through the system.
Pressure Switch	Monitors the condition of the pressure switch(s).
	LED is ON when the pressure switch(s) are in
	their correct state.
Ignitor Current	Monitors current flow through the ignitor element.
	LED is ON when current flow through the ignitor
	is sensed.
Gas Valve	Monitors Gas Valve output. LED is ON when
	the output relays supplying power to the gas
	valve(s) is closed.
Flame Sense	Monitors the Flame Sense Rod. LED is ON
	when a signal from the flame rod is sufficient to
	indicate flame.
Blocked Inlet	Indicates a blockage or interference at the ap-
	pliance air inlet.
Blocked Flue	Indicates a blockage or interference at the ap-
	pliance flue.
Blower Fail	Indicates an error/malfunction in the blower
	motor circuit.
Circulate Fail	Indicates an error/malfunction in the circulating
	pump circuit.
Ignition Fail	Indicates a malfunction in the ignition system
	circuit.

7