5.0
Maintenance
•
Troubleshooting Guide
LS
Series
43
Check to make sure gas pressure is within minimum and
maximum inputs, as indicated on burner rating plate.
Is gas pressure OK?
Were the gas lines purged of air?
Is the heater properly
grounded? Is the heater’s
polarity correct?
With micrometer, check
amperage at flame rod. Is it
greater than 1.0 microamps?
Check to make sure flame
sensor wire is OK. If so,
then replace circuit board.
Sensing rod is faulty or flame
is weak. Check to make sure
heater is operating at proper
gas pressure as indicated on
burner rating plate and then, if
needed, replace sensing rod.
Replace gas valve.
Yes
Correct problem.
Correct problem.
No
No
Yes
Yes
No
Purge gas line.
No
Yes
Confirm manifold pressure is
correct and/or gas orifice is not
plugged and is the correct size.