18
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT PLUS
®
DIRECT VENT GAS FIREPLACES (MPD33/35/40/45) • CARE AND OPERATION INSTRUCTIONS
When ordering repair parts, always provide:
1. The model number of the appliance.
2. The serial number of the appliance.
3. The part number.
4. The description of the part.
5. The quantity required.
6. The installation date of the appliance.
If you encounter any problems or have any
questions concerning the installation or
application of this system, please contact
your dealer or distributor.
LENNOX HEARTH PRODUCTS
1508 Elm Hill Pike, Suite 108
Nashville, TN 37210
visit us at www.LennoxHearthProducts.com
1-800-
655-2008
PRODUCT REFERENCE INFORMATION
We recommend that you record the important
reference information about your fi replace in
the space provided below.
Please call Lennox Hearth Products for
the phone number of your nearest Lennox
Hearth Products dealer who will answer your
questions or address your concerns.
Fireplace Model Number ________________________________________________
Fireplace Serial Number _________________________________________________
Date Installed _________________________________________________________
Type of Gas Used in Fireplace ____________________________________________
Dealer Name _________________________________________________________
TP-TH
TP
TH
APPLIANCE- MOUNTED
ON/OFF SWITCH
BK/W(1)
BK/W(1)
WALL-MOUNTED ON/OFF SWITCH (OPTIONAL)
THERMOSTAT (OPTIONAL)
JUNCTION BOX
BLACK
W
GR
120 V
AC
WALL MOUNTED CONFIGURATION FOR FAN SWITCH (OPTIONAL)
BK
R
THERMOPILE
GAS VALVE
FAN
(OPTIONAL)
WALL RECEIVER (OPTIONAL)
Figure 16: Wiring Diagram—
Millivolt Gas Valves
Figure 17: Wiring Diagram—Electronic Gas Valves
P/N 580491-01
JUNCTION BOX
120V AC
REMOTE RECEIVER
ON/OFF SWITCH
WALL SWITCH
LIMIT SWITCH
B-VENT MODELS
ONLY
AC/DC
POWER
ADAPTOR
HOT
NEUTRAL
OPTIONAL
GROUND
BATTERY HOLDER
DFC WIRE HARNESS
SPARK WIRE CABLE
PILOT GROUND WIRE
PILOT
SENSOR
CABLE
HOOD
IGNITER ROD
FLAME SENSOR
PILOT TUBE
OPTIONAL CPI SWITCH
OFF (O) = INTERMITTENT PILOT MODE
ON (-) = STANDING PILOT MODE
PROFLAME DFC BOARD
PROFLAME VALVE
ELECTRONIC PILOT ASSEMBLY
B = BLACK
BR = BROWN
GY = GRAY
PU = PURPLE
R = RED
BL = BLUE
G = GREEN
O = ORANGE
W = WHITE
Y = YELLOW
WIRING COLOR CODE
B
B
B
R
R
W
W
B
B
B
B
BL
BL
G
G
O
Y
Y
R
R
Y
W
G
G
O
SCHEMATIC REPRESENTATION ONLY
CAUTION: LABEL ALL WIRES
PRIOR TO DISCONNECTION WHEN
SERVICING CONTROLS. WIRING
ERRORS CAN CAUSE IMPROPER
AND DANGEROUS APPLIANCE
OPERATION.
ORDERING REPLACEMENT PARTS
A complete parts list is found at the end of
this manual. Use only parts supplied from
the manufacturer.
With proper care and maintenance, your
appliance will provide many years of
enjoyment. If you should experience any
problem, fi rst refer to the troubleshooting
guide in this manual. If problem persists,
contact your Lennox Hearth Products dealer
or distributor.
Normally, all parts should be ordered through
your Lennox Hearth Products distributor
or dealer.
Parts will be shipped at prevailing prices at
time of order.
WIRING DIAGRAMS
Wiring diagrams are provided here for
reference purposes only. This information is
also provided on schematics attached directly
to the appliance on a pullout panel located
within the control compartment.