Mr. Heater GAS FIRED INFRA-RED WORKSHOP HEATER MH25LP / MH25NG - Manuel (Page 6)

• This heater may be mounted on any wall;
however, it is recommended that the heater be
mounted in the middle of the wall opposite any
overhead doors.
• When selecting installation locations for this
heater ensure that the opening of any exterior or
interior doors or windows will not violate mini-
mum clearances or contact any heater compo-
nents.
• If an overhead door is installed in the building,
verify that the heater is not installed in such a
way as to interfere with door operation and verify
that the door in its open position will not reduce
clearances below the minimum requirements.
Never mount the heater in such a way that
would position the heater above an opened
overhead door.
• In most cases the infiltration around your
uninsulated entry doors and windows will provide
enough air flow for efficient heater operation.
Unrestricted air flow during heater operation is essential
to prevent the area above the installed heater from
overheating. If your workshop/utility building is tightly
insulated (including windows, doors, openings, etc.) the
following ventilating methods must be followed:
• A single exhaust vent is supplied with your
heater for your convenience. This vent must be
located above the heater (preferably at the
highest point in the building interior) and it must
vent to the exterior of the building. An additional
vent is available from the factory for those having
a finished workshop or utility building.
• An intake vent, or equivalent, from the exterior of
the building and having an effective area of 75
square inches must be located below the heater
(preferably within 2 feet of the building’s floor).
• Openings equivalent to intake vent would be:
partially open doors and partially open windows.
• Openings of this size (5 inch by 13 inch, or 3
inch by 25 inch) will prevent dangerous heat
buildup above the heater.
Ensure that no gas lines or electrical wiring or conduits
will interfere with mounting of the heater to the wall.
Depending on local codes and requirements and the
installer’s skill level, the sizing and installation of gas
lines required to supply the heater may require the
assistance of a professional. If in doubt as to these
requirements, discuss the requirements of this manual
with the dealer from whom the heater was purchased
and your gas supplier, or call our customer service
department at 1-800-251-0001.
The selection of the thermostat mounting location is
critical to efficient and effective heater operation.
• The thermostat should be mounted about 5 feet
above the floor where air can circulate freely
around it.
• The thermostat should not be mounted directly
to a cold exterior wall without an insulated
mounting block.
• The thermostat should not be mounted in direct
drafts.
• The thermostat should not be mounted directly
below the installed the heater.
• The thermostat should not be installed at a
distance that is farther from the heater than the
length of the thermostat cable.
2. HEATER MOUNTING INSTRUCTIONS
After selecting the heater installation location and the
thermostat location and after verifying and ensuring that
all of the above placement requirements are fulfilled,
mount the heater as follows:
A. Determine how you wish to install the vent based on
the construction of the building and your personal
preference. (i.e., do you wish the flanged (finished)
side on the interior or the exterior of the building or
do you want two vents so that both exterior and
interior will be finished?) If needed, order an
additional vent from the factory. Our address and toll
free phone number are on the rear cover of this
manual. Install the vent as follows:
1. See Figure 3 for dimensions and information on
the vent.
2. Select a place as high above the heater as
possible in accordance with the above require-
ments and ensure that the vent or vents will not
contact or interfere with existing building sys-
tems (i.e., ducts, wiring, plumbing, etc.)
3. Place the unfinished side of the vent against the
wall in its elected location and trace its dimen-
sions on the wall with a pencil or other suitable
marker.
4. Cut or otherwise open a hole in the wall, or walls
for finished buildings, having the dimensions of
the unfinished side of the vent.
5. Install the vent or vents as desired and retain
with 4 suitable fasteners through the predrilled
holes in vent flange.
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Installation instructions and Owner’s Manual Model # MH25NG/LP HS25NG/LP