Lennox Merit MPE36 User manual


Service Manual
Lennox Electric Fireplaces
Merit Series
MPE36
MPE33


Contents
• Removal Log Grate page 3
• Removal of Logs/Ember page 3
• Changing ember bulbs page 4
• Removal of glass panel page 5
• Component identification page 7
• Confirmpower 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
• Optional wall thermostat page 16
• Optional 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 switches 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 wiring 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 with 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: [phone]


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.
16-18 VAC
Probes connected to
transform wire terminals


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


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


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.


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


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


Wires for optional
controls
• The junction box
contains two wires that
may be used for an
optional wall switch to
control the flame
and/or an optional
thermostat to control
the heater.
• A length of black and
white wire is provided for
the connection of an
optional wall mounted
thermostat kit.


Electrical junction box
• A length of red
wire may be
bundled in the
bottom of the
junction box.
• This allows
operation of the
fireplace from
an optional wall
mounted switch.
• See the
drawing for
proper wiring
• Note: to
operate the
fireplace from
the wall switch
the unit
mounted power
switch must be
in the ‘off’
position.


Control board
• Replacement part # H1625
– Contains:
– Control Board
– Remote Receiver
Procedure for replacing control board:
•Disconnect Power Supply by
unplugging power cord or
turning off circuit breaker.
• Orient replacement board to match
defective board.
• Hold replacement board directly
below defective board.
• Remove one wire at a time from
the defective board and connect it
to the replacement board.
• Repeat until all wires have been
transferred.
• Use needle nose pliers to squeeze
the plastic corner fasteners to
release the defective board.
Remove defective board
• Place replacement board over
corner fasteners and push to lock
in place.
• Confirm all connections with the
wiring diagram.
• Restore power and test fireplace
functions.


120 VAC to transformer
24 VAC from
transformer to board
Temperature
sensor-heater
Black/Black
Control Panel Switch
Main Power on/off
(also to optional wall
switch)
Red/Red
Line voltage to
Heater Elements
Red
Flame/Ember on/off
switch
Red/Black
Control board wiring


Black wire from board to
fusible link
L-R1 & L-R2: Red wires
(hot) to heater element
L-FAN: Black wire
(hot) to fan motor
L-M: Brown wire
(hot) to flame motor
L-Light: Yellow wire
(hot) to ember lights
P-L: Black wire (hot) from junction box- to board- to
fusible link
L-Flame: Purple
wire(hot) to flame
wheel lights
Control Board Wiring (Hot)