Test 5: Calling For Heat - No Blower Operation - A.O. Smith SERIES 120 Service Handbook

TEST 5: CALLING FOR HEAT - NO BLOWER OPERATION

Conditions:
• Power on
• Plugs in Receptacles
• Red " Call for Heat" LED - ON
• Blower (Draft Inducer) off
Note flash code on ignition control board diagnostic LED.
TEST 5
IF.........
Pin 1 to ground check has no voltage
Pin 1 to ground has voltage
Pin 3 to ground has no voltage
Servicing should only be performed by a Qualifi ed Service Agent
TROUBLESHOOTING
Water Heater Control - Thermostat
"Call for Heat"
LED Indicator
Diagnostic LED
Indicator
120
Figure 24
then............
• reset control by interrupting power. Note possible reasons for this from flashing LED code.
• replace ignition board.
Proceed
• check wiring harness and plugs.
• replace blower.
Ignition Control Board
Ground
31