3
Installation Instructions and Owner’s Manual
Unvented Natural Gas Vent Free Room Heaters
9.
Operating heater above elevations of 4,500 feet
could cause pilot/ODS to shutdown heater.
10. Always run heater with control knob in a locked
position. Never set control knob between locked
positions. Poor combustion and higher levels of
carbon monoxide may result if control knob is left
between locked positions.
DANGER
: Carbon monoxide poisoning may lead to
death.
Carbon Monoxide Poisoning:
Early signs of carbon monoxide poisoning resemble
the fl u, with headaches, dizziness, or nausea. If you
have these signs, the heater may not be working
properly. Get fresh air at once! Have heater serviced.
Some people are more affected by carbon monoxide
than others. These include pregnant women, persons
with heart or lung disease or anemia, those under the
infl uence of alcohol, and those at high altitudes.
Natural Gas:
Raw natural gas is odorless. An odor making agent is
added to natural gas, which helps you detect a natural
gas leak. However the odor added to natural gas can
fade. So natural gas may be present even though no
odor is detected. Make certain you read and understand
all warnings. Keep this manual for reference. It is your
guide to safe and proper operation of this heater.
PRECAUTIONS:
1. 20,000 or 30,00 BTU heater may not be installed
in a bedroom or bathroom, or any place where a
strong wind would shut down the appliance.
2. This heater needs outside ventilation air to run
properly. The Oxygen Depletion Sensor (ODS)
safety shutoff system shuts down the heater if not
enough fresh air is available. See
Fresh Air for
Combustion and Ventilation
, pages 4 through 6.
3. Keep all air openings in heater clear, free of debris
or any blockage. This will insure that enough air for
proper combustion enters the heater.
4. If heater shuts off, do not relight until you provide
fresh, outside air. If heater keeps shutting off, it
requires servicing.
5. Turn off and unplug heater and let cool before
servicing. Only a qualifi ed service person should
service and repair heater.
6. Do not run heater:
•
Where fl ammable liquids or vapors are used or
stored
•
During dusty conditions.
7. Before using furniture polish, wax, carpet cleaner
or similar products, turn heater off. If heated the
vapors from these products may create a white
powder residue within burner box or on adjacent
walls or furniture.
8. Do not use heater if any part has been underwater.
Immediately call a qualifi ed service technician to
inspect the room heater and to replace any part of
the control system and any gas control which has
been underwater.
SPECIFICATIONS
**Operating heater above elevations of 4,500 feet could cause pilot/ODS to shutdown heater.**
MHVFRD20TB
/
MHVFRD20T NG
MHVFRD30TB /
MHVFRD30T NG
MHVFBF20TB /
MHVFBF20 NG
MHVFBF30TB /
MHVFBF30T NG
BTU
(Available) 20,000 30,000 20,000 30,000
Type of Gas
Natural Gas Only
Natural Gas Only
Natural Gas Only
Natural Gas Only
Ignition
Battery ignitor (1-AA) Battery ignitor (1-AA) Battery ignitor (1-AA) Battery ignitor (1-AA)
Pressure Regulator Setting
4.5 Inches of Water
4.5 Inches of Water
4.5 Inches of Water
4.5 Inches of Water
Inlet Gas Pressure (Maximum)
14 Inches of Water
14 Inches of Water
14 Inches of Water
14 Inches of Water
Inlet Gas Pressure (Minimum)
7 Inches of Water
7 Inches of Water
9 Inches of Water
9 Inches of Water
Electrical Rating /Blower
120V, 60Hz , 1
120V, 60Hz , 1
120V, 60Hz , 1
120V, 60Hz , 1
Thermostatic Control
Yes
Yes
Yes
Yes
Clearances: inches (mm)
Top
36” (915cm)
36” (915cm)
36” (915cm)
36” (915cm)
Sides
10” (254cm)
10” (254cm)
10” (254cm)
10” (254cm)
Floor (min to top of carpet)
3” (76cm)
3” (76cm)
3” (76cm)
3” (76cm)
Fabric / fl ammable objects
36” (915cm)
36” (915cm)
36” (915cm)
36” (915cm)
WARNING:
An unvented heater having an input
of more than 10,000 Btu/hr (2 931W) shall not be
installed in a bedroom or bathroom.
