29
LENNOX HEARTH PRODUCTS • MERIT PLUS
®
B-VENT GAS FIREPLACES (MPB33/35/40/45) • CARE AND OPERATION INSTRUCTIONS
SYMPTOM
POSSIBLE CAUSES
CORRECTIVE ACTION
Nothing happens when
the fireplace is turned
ON/OFF.
Remote control system is not
functioning properly.
To use the remote control system, the wall switch plate must be set to REMOTE.
Manually operate the fireplace using the wall switch (ON/OFF).
Replace the batteries in the handheld remote and/or behind the wall switchplate.
Unit is not receiving power.
Check/replace batteries behind the wall switchplate.
Replace unit battery backup.
Check building circuit breakers to ensure power is on to the fireplace.
Gas is not reaching the fireplace.
Check the gas supply and gas shutoff valves (call a service technician, if required).*
The main burner does
not light and the igniter
is sparking.
Gas is not reaching the fireplace. Check the gas supply and gas shutoff valves (call a service technician, if required).*
Unit is not receiving power.
Replace unit battery backup.
Loose wires to the valve.
Check control compartment for any obvious loose wiring (call a service technician).
Loose wires to ignition module. Check control compartment for any obvious loose wiring (call a service technician).
Air in the gas line.
Purge gas line of air (call a service technician).
The burner lights, then
immediately goes out.
Gas is not reaching the fire-
place.
Check the gas supply and gas shutoff valves (call a service technician, if required).*
Loose wires to the valve
or ignition module.
Check the gas supply and gas shutoff valves (call a service technician, if required).*
Pilot flame is not engulfing the
sensor.
Call a service technician.
Obstructed vent system.
Call a service technician.
Soot is present on the
glass and panels.
Initial fireplace operation.
A white film may develop on the glass during the first few fires as part of the burn-in
process.
The first few times you use the fireplace, clean the glass after each use (AFTER THE
GLASS HAS COMPLETELY COOLED); otherwise, the white film will bake onto the glass
and become difficult to remove.
See glass cleaning instructions in the MAINTENANCE section of this manual.
Excessive flame impingement
on panels and fireplace ceiling.
Properly position the media as detailed in the instructions provided with the Media Kit.
Improper air shutter opening.
Open the air shutter by adjusting the air shutter adjustment lever according to the in-
structions in this manual.
Improper vent restrictor setting. Open the air shutter by adjusting the air shutter adjustment lever according to the in-
structions in this manual.
Poor flame and/or blue
flame.
Door seal is not properly
aligned, causing gaps and
air leaks.
Remove and realign the door so the gasket seal is fully engaged around the door frame.
Air shutter not correctly set.
Adjust air shutter as instructed on
Pages 17 and 18.
*The unit may have multiple gas supply shutoffs (main gas supply valve in house, gas supply valve in fireplace control compartment, and/or ad-
ditional shutoff valve near fireplace).
TROUBLESHOOTING GUIDE: ELECTRONIC GAS CONTROL SYSTEM
NOTE: Before troubleshooting the gas control system, make sure the external gas shut off valve (located at gas supply inlet) is in the “ON”
position.
NOTE: Valve system troubleshooting should only be performed by a qualified service technician.
