Lennox Hearth LBV-3824MN Indoor Fireplace User Manual


 
15
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
TROUBLESHOOTING THE ELECTRONIC IGNITION SYSTEM
N
ote: Before troubleshooting, be sure that the appliance main line gas shut-off valve, the gas control valve and the wall switch are in
the ON position.
Important: Valve system troubleshooting should only be accomplished by a qualified service technician.
SYMPTOM POSSIBLE CAUSES CORRECTIVE ACTION
Ensure damper control lever is locked in the open position, all the way to the
right. If the damper control lever is locked in the open position troubleshoot
through Steps B., C. and D. below. If the main burner will still not light,
determine if the damper switch is defective and replace if necessary.
See Below.
Reset the limit switch button. If still not working, access the leads attached to
the limit switch and check for continuity. If no continuity, replace limit switch.
Disconnect the two black wires from the wire nuts. Test switch(s) for
continuity with a multimeter. If continuity is not indicated, switch(s) is
defective and must be replaced.
Note: Before replacing OFF/ON switch, be sure to check wiring for loose
connections or broken wires and repair as needed.
Check main burner orifice(s) for stoppage. Clean or replace.
Check vent system for obstructions.
A. Damper closed or
Damper Switch defective.
B. Faulty Valve System.
C. Faulty limit switch.
D. OFF/ON or wall switch
defective.
A. Burner orifice plugged.
B. Obstructed vent system.
1. Burner will not light.
2. Burners come ON but
go OFF.
Turn Off Gas Supply
Assure Valve Switch Is In ON Position
Disconnect Control Harness
Set Thermostat To Call For Heat
Check For Proper Voltage At Control Harness
(See Insert A). Voltage Should Be 24V
Between Thermostat Or Pressure Switch
And 24V Common And 24V Hot.
Line Voltage Power
Low Voltage Transformer
Limit Controller
Thermostat
Wiring
2
CHECK
START
NO
Plug Control Harness Into Valve. Wait For
Internal Check Delay.
YES
Igniter Warms Up And Glows Red.
With Pilot Burner Cable Connected, Measure
Voltage At Valve HSI Element Output. 24V
Nominal. (See Insert B)
NO
Replace Igniter/Flame Rod Assembly.
YES
Replace Valve.
NO
Turn On Gas Supply. Pilot Burner Lights.
Check That Pilot Gas Is Flowing. Wait To
Assure Plot Gas Tubing Is Purged. Recycle
Call For Heat If Necessary.
NO
YES
NO
YES
YES
1
Measure Voltage Between 24V Hot And 24V Common
Leads To Valve Control. Must Measure At Least 19.5
VAC With Igniter Powered (See Insert A). To Identify
Proper Lead, This Check Must Be Done With The
Valve Control Connected And Igniter Powered.
Check Transformer And
Line Volt Supply.
NO
Replace Pilot Assembly.
YES
Check That Pilot Flame Makes Good Contact With
Pilot Burner Flame Rod.
Check For Good Electrical Connection Through The
Pilot Tubing.
If Both Of The Above Are Good, Replace Igniter/Flame
Rod Assembly.
Cycle Thermostat Off And Back On.
YES
Main Valve Opens And Main Burner Lights.
NO
YES
System Is Okay.
YES
Main Burner Lights.
NO
2
1
Igniter Will Cycle Off And Back On Once During
The 90 Second Ignition Trial. All Voltage
Measurements Must Be Taken While The Igniter
Is Powered.
When Measured Voltage At Connections, Use
Care To Assure Terminals Are Not Damaged.
Replace Valve.
Replace Valve.
24 Volt Hot
End View Of
Control Harness
Connector
24 Volt
Common
24 Volt
Switched
Check For Damaged Or Missing Terminals
In Connector
Insert A
Igniter Terminals
Insert B
2
1