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NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT
®
PLUS DIRECT VENT GAS FIREPLACES (MPD33/35/40/45) • CARE AND OPERATION INSTRUCTIONS
GENERAL INFORMATION
The fireplace models covered in this manual
are direct-vent sealed combustion gas fireplace
heaters designed for residential application.
These direct-vent appliances operate with the
combustion chamber completely isolated from
the indoor environment.
All air for combustion is brought in from the
outside and exhaust gases are vented through
the same direct-vent, co-axial (intake/exhaust)
vent system.
The Millivolt appliances have a millivolt gas
control valve with piezo ignition system. If any
optional accessories which require electrical
power are being installed, the electrical power
must be provided at the time of appliance in-
stallation.
The Electronic appliances are designed to
operate on either natural or propane gas. An
electronic intermittent pilot system provides
safe, efficient operation. External electrical
power is required to operate these units.
These appliances comply with National
Safety Standards and are tested and listed
by OMNI-Test Laboratories, Inc. (Report No.
116-F-13-4) to ANSI ZZ21.88 (in Canada, CSA-
2.33), and CAN/CGA-2.17-M91 in both USA and
Canada, as vented gas fireplace heaters.
The Installation must conform to local codes
or, in the absence of local codes, with the
National Fuel Gas Code, ANSI Z223.1/NFPA
54-latest edition, or the Natural Gas and Propane
Installation Code, CAN/CSA B149.1-latest edi-
tion. The appliance, when installed, must be
electrically grounded in accordance with local
codes or, in the absence of local codes, the
latest edition of the National Electrical Code,
ANSI/NFPA 70, or the Canadian Electrical Code,
CSA C22.1 - latest editions.
WARRANTY INFORMATION
Your gas appliance is covered by a limited
twenty-year warranty. You will find a copy of
the warranty accompanying this manual. Please
read the warranty to be familiar with its coverage.
Retain this manual. File it with your other docu-
ments for future reference.
Failure to comply with the installation
and operating instructions provided
will result in an improperly installed
and operating appliance, voiding its
warranty.
Do not attempt to alter or modify the
construction of the appliance or its com-
ponents. Any modification or alteration
may void the warranty, certification, and
listings of this unit.
APPLIANCE OPERATION NOTICES
Do not operate appliance with the glass
front removed, cracked, or broken.
These fireplaces are vented gas appli-
ances. Do not burn wood or other
material in these appliances.
This appliance is only for use with the
type of gas indicated on rating plate. This
appliance is not convertible for use with
other gases, unless a certified kit is used.
These appliances are designed to operate
on natural gas or propane gas only. The
use of other fuels or combinations of
fuels will degrade the performance of this
system and may be dangerous.
Provide adequate clearances around
air openings and adequate accessibility
clearance for service and proper opera-
tion. Never obstruct the front openings
of the appliance.
Do not use this appliance if any part has
been under water. Immediately call a
qualified service technician to inspect
the appliance and to replace any part of
the control system and any gas control
that has been under water.
These fireplaces are designed as supple-
mental heaters. Therefore, it is advisable
to have an alternate primary heat source
when installed in a dwelling.
APPLIANCE INSTALLATION, SERVICE,
AND MAINTENANCE NOTICES
IMPORTANT: Improper installation,
adjustment, alteration, service, or
maintenance can cause injury or property
damage. Refer to this manual. For
assistance or additional information,
consult a qualified installer, service
agency or the gas supplier.
Only trim kit(s) supplied by the manufac-
turer shall be used in the installation of
this appliance.
Draft relief openings must not be covered
or blocked.
These appliances must not be connected
to a chimney or flue serving a separate
solid fuel burning appliance.
Any change to this appliance and/or
its operating controls is dangerous.
Improper installation or use of this
appliance can cause serious injury or
death from fire, burns, explosion or
carbon monoxide poisoning.
CARBON MONOXIDE POISONING: Early
signs of carbon monoxide poisoning are
similar to the flu with headaches, dizzi-
ness and/or nausea. If you have these
signs, obtain fresh air immediately.
Turn off the gas supply to the appliance
and have it serviced by a qualified
professional, as it may not be operating
correctly. Some people are more
affected by carbon monoxide than others,
including pregnant women, people with
heart or lung disease or anemia, those
under the influence of alcohol, and those
at high altitudes.
Turn off gas and electrical power to the
fireplace and allow it to cool before
cleaning or servicing the appliance.
The vent termination is hot while in
operation and for a period of time fol-
lowing the use of the fireplace. Young
children should be carefully supervised
when they are in the same area as a hot
termination
