Pre-Service - A.O. Smith BTH 120 Service And Parts Manual

CHECK THAT:
• Tank is full of water
• Exhaust and intake vent do not exceed allowable limits
• All plugs into boards are secure
• Condensate hose is drained and open
• 115-120 VAC is supplied to the heater (including polarity
check a neutral to ground check results in "0" volts reading)
• Proper (natural or propane) gas is supplied
Condition:
After 20 second prepurge is complete
No main burner
• On/Off switch is off
• Igniter wires disconnected from CN5
• Multimeter set to "continuity check"
2000 OHMS scale
STEP 1. Check continuity through the leads of the igniter.
IF...
a continuity range of 50-300 ohms is not present
a continuity range of 50-300 ohms is present
A. O. Smith Water Products Company
Irving, Texas 2000©
TROUBLESHOOTING
PRE-SERVICE TIPS
CONTINUITY CHECKS
STEP 1 - IGNITER CONTINUITY CHECK
Connector from CN5
THE
rep
rea
18
Service Handbook
Training Department