Lennox Merit MPE36, Merit MPE33 Service Manual

Service Manual
Lennox Electric Fireplaces
Merit Series
MPE36 MPE33
Contents
Removal Log Grate page 3
Changing ember bul bs page 4
Removal of glass panel page 5
Component identification page 7
Confirm power supply page 8
Transformer testing page 9
Flame panel removal page 11
Flame cylinder bulb replacement page 12
Lights: Flame and Ember page 13
Electrical junction box access page 15
Opti onal wall thermostat page 16
Opti onal wall switch page 17
Control board page 18
Remote control sensor page 23
Remote control feature page 24
Heater thermostat operation page 24
Flame cylinder motor replacement page 25
Control panel sw itches page 29
Remote control does not function page 31
Heater sensor page 32
Heater access page 33
Testing the heater/blower page 34
Junction box w iring page 42
Parts List page 45
Read this first
This manual is provided as a tool to assist professional service personnel working on Lennox Electric Fireplaces.
Do not attempt to service this electrical appliance if:
You have not been trained
how to safely service electrical appliances.
You are not familiar w ith the
use of electrical diagnostic tools.
Disconnect the power supply prior to attempting any service.
Electrical Shock Hazard
Read this manual and the installation and operation instructions for this appliance before attempting any service.
If you have any questions
regarding this appliance contact Lennox Technical Service at: (800) 655-2008
Remove Grate and Log
Set
The grate must be removed before removing the log set.
Remove the two screws that secure the grate in place and remove the grate.
Place your thumbs on the front edge of the ember base approximately 1/3 of the way in from the ends of the log set.
Push towards the back causing the ember base to flex. As you push gently lift the front edge of the ember base. The log set and ember base may be lifted up and out of place.
Changing ember bulbs
Remove logs and grate (see page 3)
On MPE36R replacement bulbs will be found in a pocket in the log set
Lift at the front of the plastic ember bed to “pop” it up and release it.
Remove ember bed.
Remove spring retainer from bulb.
Remove defective bulb.
Using plastic gloves or a small plastic bag to prevent oils from your hands from coating the bulbs, insert the replacement bulb in the socket and replace the retaining spring.
Replace ember bed
Replace logs and grate.
Removal of rear glass
panel
Remove logs and grate
Remove ember bed
Remove screws from right and left retaining brackets
Remove screws from top retaining bracket
Caution: wear protective gloves when removing or handling the glass panel.
Gloves will help prevent cuts and will also prevent the oils from your hands from staining the surface of the glass panel
Removal of rear glass
panel (continued)
Grasp glass panel at top and tip forward.
With panel loose, grasp on top and bottom edges to remove from fireplace.
Components
Control board
Transformer
Remote control receiver
Flame cover panel
Motor and Flame cylinder
Fuse location
Power supply
When the electric fireplace is initially connected to a power supply:
By plugging in the power
cord to a receptacle
By turning on the circuit
breaker (hard wired connection at the junction box)
The control board will emit two loud “beeps” to confirm “power up”.
If you do not hear these ‘beeps”:
Confirm that the circuit
breaker is “on”
Confirm power to the
receptacle.
Is an external switch
controlling the power to the fireplace? If so it must be on.
If power is available to the fireplace and the two “beeps” are not sounded at”power up”, look for:
Transformer failure (page 9) – Control board failure
Control Board- beeps twice to confirm “power up”
Testing Transformer
Caution: electrical shock hazard!
This tests confirms that line voltage 120 VAC is available to power the transformer.
Place multimeter leads on control board terminals as shown.
Line voltage should be between 105 VAC – 127 VAC.
To test the transformer:
•Remove the low voltage connector (two red wires) from the control board as shown. On the side of the connector two silver terminals will be visible.
•Set your Multimeter to test AC voltage. Touch the probes to the two silver connectors on the transformer wires. Voltage should between 16 – 18 VAC
•When the transformer is reconnected to the board there should be two “beeps” should be heard confirming “power up” of the control board.
Probes connected to transform wire terminals

16-18 VAC
Removal of flame panel
Use wire cutters to clip the plastic wire tie binding the remote control receiver wire.
Use a screwdriver to remove the screws on the right and left edges of the flame cover panel.
The panel may be placed upon the floor in front of the fireplace during service
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Changing bulbs in flame
cylinder
Grasp the top of the flame cylinder and squeeze gently disengaging the flame cylinder cover.
Lift the cover off to expose the two flame bulbs.
Caution: The edges of the flame cylinder may be sharp! Wear protective gloves to prevent injury
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Lights: Flame and Ember
With the flame cylinder cover removed, the two bulbs are visible.
When the flame switch is activated the bulbs should light and the flame wheel should turn.
Use the remote control to brighten and to dim the flame bulbs and the ember bed bulbs.
When testing voltage to the ember and flame lights:
If the lights are
activated by the control panel switch voltage will be approximately 114VAC
If the lights are
activated by the remote control the dimmer function will vary the voltage from approximately 4 VAC (low) to 114 VAC at the high setting.
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If ember and flame lights
fail to operate
•Check the in-line fuse located to the right of the control board.
•Perform a continuity test on the fuse. If the multimeter displays “1” the fuse has blown and must be replaced.
•If the bulbs and fuse test “OK” , check the continuity of the control panel switch (power On/Off) and (lights On/Off)
•If switches test OK then test control board.
•L- Light to N-Light =114VAC
•L-Flame to N-Flame = 114VAC
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Access to electrical
junction box
Turn off power to the fireplace by either unplugging the power cord or setting the circuit breaker in the home’s electrical panel to the “off” position.
Remove screws in junction box cover.
Wire connections to a) factory supplied
power cord or b) Romex power supply should be as follows:
120VAC linefireplace
black black white blue N1
blue N2 white green green/yellow
          
For 240 VAC wiring see page 42
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