MHVFB30NGT
MR. HEATER, INC., 4560 W. 160
TH
ST., CLEVELAND, OHIO 44135 · 800-251-0001
2016 - CB
UNVENTED NATURAL GAS FIRED ROOM HEATER
OPERATING INSTRUCTIONS
AND OWNER’S MANUAL
READ INSTRUCTIONS CAREFULLY: Read and follow all instructions. Place instructions in a safe
place for future reference. Do not allow anyone who has not read these instructions to assemble,
light, adjust or operate the heater.
Blue Flame Heaters
MHVFBF20NGBT
(BLOWER INCLUDED)
MHVFBF20NGT
(BLOWER SOLD SEPARATE)
MHVFBF30NGBT
(BLOWER INCLUDED)
MHVFBF30NGT
(BLOWER SOLD SEPARATE)
Plaque Heaters
MHVFRD20NGBT
(BLOWER INCLUDED)
MHVFRD20NGT
(BLOWER SOLD SEPARATE)
MHVFRD30NGBT
(BLOWER INCLUDED)
MHVFRD30NGT
(BLOWER SOLD SEPARATE)
WARNING: If the information in this manual is not followed exactly, a fi re or explosion may result causing
property damage, personal injury, or loss of life.
- Do not store or use gasoline or other fl ammable vapors and liquids in the vicinity of this or any other appliance.
- WHAT TO DO IF YOU SMELL GAS
• Shut off gas supply
• Do not try to light any appliance
• Do not touch an electrical switch; do not use any phone in your building.
• Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fi re department.
- Installation and service must be performed by a qualifi ed installer, service agency, or the gas supplier.
WARNING: This is an unvented gas-fi red heater. It uses air (oxygen) from the room in which it is installed.
Provisions for adequate combustion and ventilation air must be provided. Refer to Fresh Air for Combustion
and Ventilation section on page 4 of this manual.
WARNING: Improper installation, adjustment, alteration, service or maintenance can cause injury or property
damage. Refer to this manual for correct installation and operational procedures. For assistance or additional
information consult a qualifi ed installer, service agency, or gas supplier.
This appliance may be installed in an aftermarket permanently manufactured (mobile) home, where not prohibited
by local codes. This appliance is only for use with the type of gas indicated on the rating plate. This appliance is not
convertible for use with any other gas.
INSTALLER: Leave this manual with the appliance. CONSUMER: Retain this manual for future reference.
2
Installation Instructions and Owner’s Manual
Unvented Natural Gas Vent Free Room Heaters
CONTENTS
WARNINGS ........................................................................ 2
SPECIFICATIONS .................................................................3
PRECAUTIONS ....................................................................3
IGNITION SYSTEM BATTERY INSTALLATION ....................... 4
BLOWER FAN CONTROL SWITCH OPERATION ....................4
DETERMINING THE TYPE OF HEATER LOCATION SPACE .....5
INSTALLATION ...................................................................6
FASTENING HEATER TO WALL ............................................7
FLOOR MOUNTING AWAY FROM WALL .............................8
CONNECTING TO GAS SUPPLY ........................................... 8
OPERATING YOUR HEATER ............................................... 10
CLEANING AND MAINTENANCE .......................................11
TROUBLESHOOTING ........................................................ 14
EXPLODED-VIEW PARTS DRAWING ................................... 16
PARTS LIST ....................................................................... 17
WARRANTY .................................................................... 20
In order to provide the best service possible Mr. Heater is now giving you
more ways to get in touch with us:
WEBSITE: Mr. HeaterÊs full line of product are now at:
WWW.MRHEATER.COM
FACEBOOK: Find us on Facebook
TWITTER: Find us on twitter
YouTube: There are now informational videos on YouTube.
SOCIAL MEDIA
WARNINGS
IMPORTANT: Read this owner’s manual carefully and completely before trying to assemble, operate, or
service this heater. Improper use of this heater can cause serious injury or death from burns, fi re, explosion,
electrical shock, and carbon monoxide poisoning.
WARNING: This appliance is equipped for natural
gas. Field conversion is not permitted.
WARNING: Do not use any accessory not
approved for use with this heater.
WARNING: Any change to this heater or its
controls can be dangerous.
• Do not place clothing or other fl ammable ma-
terial on or near the appliance.
• Due to high temperatures, heater should be
kept out of traffi c and away from furniture and
draperies.
• Surface of heater becomes very hot when
running. Keep children and adults away
from hot surfaces to avoid burns or clothing
ignition. Heater will remain hot for a time
after shutdown. Allow heater surfaces to cool
before handling.
• Young children should be carefully supervised
when they are in the same room with heater.
• Make sure grille guard is in place before
running heater. If screen or grille guard is
removed for servicing it must be replaced prior
to operating the heater.
• Keep the appliance area clear and free from
combustible materials, gasoline, and other
fl ammable vapors and liquids.
• Children and adults should be alerted to the
hazard of high surface temperature and should
stay away to avoid burns or clothing ignition.
• Any safety screen or guard removed for
servicing an appliance must be replaced prior
to operating the heater
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.
4
Installation Instructions and Owner’s Manual
Unvented Natural Gas Vent Free Room Heaters
Product Features
Figure 1
SAFETY DEVICE
This heater has a pilot with an Oxygen Depletion Sen-
sor (ODS) safety shut off system. The ODS/pilot shuts
off the heater if there is not enough fresh air.
IGNITION SYSTEM / BATTERY INSTALLATION
– The heater is equipped with an electronic manual
ignitor. This system requires no matches, or other
source to light heater, but does require one AA battery
to operate ignitor. (AA Battery included).
To install or replace battery unscrew the ignitor cap
(red button), insert battery positive (+) terminal up
and replace cap.
(AA Battery included)
THERMOSTATIC CONTROL
These heaters have a control valve with a thermostat
sensing bulb. This results in the greatest heater comfort
and may result in lower bills.
BLOWER FAN CONTROL SWITCH OPERATION
On models equipped with an electrical blower. The blower
switch has three positions: MANUAL, OFF and AUT O. In
AUTO, the blower will turn on and off as the heater cycles
on and off. On MANUAL, the blower will run continuously.
To turn blower off, use the OFF position.
LOCAL CODES
Install and use heater with care.
Installation must conform to local codes or in the ab-
sences of local codes, use the latest edition of National
Fuel Gas Code ANSI Z223.1/NFPA 54.
UNPACKING
1. Remove heater from carton.
2. Remove all protective packaging applied to
heater for shipment.
3. Check heater for any shipping damage. If
heater is damaged, promptly inform dealer
where you bought heater.
FRESH AIR FOR COMBUSTION AND
VENTILATION
WARNING: This heater shall not be installed in
a confi ned space or unusually tight construction
unless provisions are provided for adequate
combustion and ventilation air. Read the following
instructions to insure proper fresh air for this and
other fuel-burning appliances in your home.
EST ABLISHING ADEQUATE VENTILATION
The following are excerpts from National Fuel Gas
Code, NFPA 54/ ANSI Z223.1, Section 5.3, Air for
Combustion and Ventilation. All spaces in homes fall
into one of the three following ventilation classifi cations:
1. Unusually Tight Construction
2. Unconfi ned Space
3. Confi ned Space
This heater must not be installed in a confi ned space or
unusually tight construction unless provisions are pro-
vided for adequate combustion and ventilation air. The
information on pages 4 through 6 will help you classify
your space and provide adequate ventilation.
Unusually Tight Construction
If your home meets all of the three following criteria you
must provide additional fresh air. See V entilation Air
from Outdoors, page 6.
Unusually tight construction is defi ned as construction
where:
a. Walls and ceilings exposed to the outside atmo-
sphere have a continuous water vapor retarder with
a rating of one perm (6 x 10
-11
kg per pa-sec-m
2
) or
less with openings gasketed or sealed and
b. Weather stripping has been added on operable
windows and doors, and
c. Caulking or sealants are applied to areas such
as joints around windows and door frames,
between wall-ceiling joints, between wall panels, at
penetrations for plumbing, electrical, and gas lines,
and at other openings.
If your home does not meet all of the three criteria
above, see Determine the Type of Heater Location
Space, page 5.
Confi ned Space and Unconfi ned Space
The National Fuel Gas Code, NFPA 54/ ANSI Z223.1
defi nes a confi ned space as a space whose volume is
less than 50 cubic feet per 1,000 Btu per hour (4.8 m
3
per kW) of the aggregate input rating of all appliances
installed in that space, and an unconfi ned space as a
space whose volume is not less than 50 cubic feet per
1,000 Btu per hour (4.8 m
3
per kW) of the aggregate
input rating of all appliances installed in that space.
Rooms communicating directly with the space in which
the appliances are installed*, through openings not
furnished with doors, are considered a part of the
unconfi ned space.
Ignitor Button
Control Knob
Grill
Front Panel
Burners
Heater
Cabinet
Fan Blower
Switch
(located on back of
heater)
*Blower not included on all units
5
Installation Instructions and Owner’s Manual
Unvented Natural Gas Vent Free Room Heaters
*Adjoining rooms are communication only if there
are odorless passageways or ventilation grills be-
tween them.
DETERMINING THE TYPE OF HEATER
LOCATION SPACE:
Use this method to determine if you have a confi ned or
unconfi ned space.
Note: the space includes the room in which you
install heater plus any adjoining rooms with doorless
passageways or ventilation grills between the rooms.
1. Find the volume of the space by multiplying room
length x width x height.
Example: Space size 18ft (length) x 18ft. (width) x 8ft.
(height) = 2592
If additional ventilation to adjoining room is supplied
with grills or openings, add the volume of these rooms
to the total volume of the space.
2. Divide the space volume by 50 cubic feet to deter-
mine the maximum Btu/hr the space can support.
Example: 2592 cu.ft. (volume of space) / 50 cu.ft. =
51.8 or 51,800 (maximum Btu/hr the space
can support)
WARNING: This heater shall not be installed in a
room or space unless the required volume of indoor
combustion air is provided by the method described
in the National Fuel Gas Code, ANSI Z223.1/NFPA
54, the International Fuel Gas Code, or applicable
local codes.
3. Add the Btu/hr of all the fuel-burning appliances
in the space such as, Vent–free heater, Gas water
heater, Gas furnace, Vented gas heater, Gas
fi replace logs, and Other gas appliances*
*Do not include direct-vent gas appliances. Direct-
vent draws combustion air from the outdoors and
vents to the outdoors.
Example: Gas water heater 40,000 Btu/hr
Vent Free Heater + 20,000 Btu/hr
Total =60,000 Btu/hr
4. Compare the maximum Btu/hr the space can support
with the actual amount of Btu/hr used.
Example: 51,800 Btu/hr (maximum Btu/hr the
space can support)
60,000 Btu/hr (Actual amount of Btu/hr
used)
The space in the above example is a confi ned
space because the actual Btu/hr used is more than
the maximum Btu/hr the space can support.
You must provide additional fresh air. Your options
are as follows:
A. Rework worksheet, and the space of an adjoining
room. If the extra space provides an unconfi ned
space, remove door to adjoining room or add venti-
lation grills between the rooms. See Ventilation Air
From Inside Building (Figure 2).
B. Vent room directly to the outdoors. See Ventilation
Air From Outdoors (Figure 3).
C. Install a lower Btu/hr heater if lower Btu/hr size
makes room unconfi ned.
If actual Btu/hr used is less than the maximum Btu/
hr the space can support, the space is an uncon-
fi ned space. You will need no additional fresh air
ventilation.
VENTILA TION AIR
Ventilation from Inside Building
This fresh air would come from an adjoining unconfi ned
space. When ventilation to an adjoining unconfi ned
space, you must provide two permanent openings: one
within 12” of the ceiling and one within 12” of the fl oor
on the wall connecting the two spaces (see options 1
& 2 of fi g. 2). You can also remove door into adjoin-
ing room (see option3, fi g 2). Follow the National Fuel
Gas Code NFPA 54/ ANSI Z223.1, Section 5.3, Air for
Combustion and Ventilation for required size of ventila-
tion grills or ducts.
Figure 2.
Figure 3.
Ventilation
Gills into
Adjoining
Room -
Option 1
Ventilation Gills into
Adjoining Room - Option 2
12”
12”
Or remove
door into
Adjoining
Room -
Option 3
INLET
AIR
OUTLET
AIR
VENTILATION CRAWL SPACE
TO CRAWL
SPACE
TO A TTIC
VENTILATION AIR
VENTILATED
ATTIC
OUTLET AIR
6
Installation Instructions and Owner’s Manual
Unvented Natural Gas Vent Free Room Heaters
*A CSA/AGA certifi ed equipment shutoff valve with
1/8” NPT tap is an acceptable alternative to test gauge
connection. Purchase a CSA/AGA certifi ed equipment
shutoff valve from your dealer .
LOCATING HEATER
This heater is designed to be mounted on the wall. The
heater can also be located on a non-combustible fl oor,
away from a wall by using the fl oor mounting stands in-
cluded with the heater. If installed on combustible fl oor-
ing such as carpeting, tile or other combustible material
other than wood fl ooring, the heater must be placed on
a wood panel the full width and depth of the appliance.
For convenience and effi ciency, install the heater:
• Where there is easy access for operation,
inspection, and service
• In the coldest part of the room.
• If planning to use fan, locate heater near an
electrical outlet.
CAUTION: If you install the heater in a home garage:
Heater pilot and burner must be at least 18 inches
above fl oor . Locate heater where moving vehicle will
not hit it.
CAUTION: This heater creates warm air currents.
These currents move heat to wall surfaces next to
heater. Installing heater next to vinyl or cloth wall
covering or operating heater where impurities (such
as tobacco smoke, aromatic candles, cleaning fl uids,
oil or kerosene lamps, etc.) are present in the air may
discolor walls.
WARNING: Never install the heater:
• In a bedroom (RD20NGT, RD30NGT,
BF20NGT or BF30NGT)
• In a recreational vehicle ·.
• Where curtains, furniture, clothing, or other
fl ammable objects are less than 36 inches from
the front, top, or sides of the heater.
• As a fi replace insert
• In high-traffi c areas
• In windy or drafty areas
WARNING: Heater must be mounted to maintain
the minimum clearances shown in Figure 4. If
possible, provide greater clearances from the fl oor,
ceiling, and joining walls.
WARNING: Rework worksheet, adding the space
of the adjoining unconfi ned space. The combined
space must have enough fresh air to supply all ap-
pliance in both spaces.
Ventilation from Outdoors
If necessary provide extra fresh air by using ventila-
tion grills or ducts. Connect these items directly to the
outdoors or spaces open to the outdoors. These include
attics* and crawl spaces. Follow the National Fuel Gas
Code NFPA 54/ ANSI Z223.1, Section 5.3, Air for Com-
bustion and Ventilation for required size of ventilation
grills or ducts.
*IMPORTANT: Do not provide openings for inlet or
outlet into attic. If attic has a thermostat-controlled
power vent, heated air entering the attic will activate
the power vent.
IMPORTANT: Vent-free heaters add moisture to
the air. Although this is benefi cial, installing heater
in rooms without enough ventilation air may cause
mildew to form from too much moisture. See Fresh
Air for Combustion and Ventilation, pages 4 through
6.
INSTALLATION
WARNING: Any change to this heater or its
controls can be dangerous.
NOTICE: This appliance is intended for supplemental
heating. Use this heater along with your primary heating
system. Do not install this heater as your primary heat
source. If you have a central heating system, you may
run system’s circulating blower while using heater. This
will help circulate the heat throughout the house. In the
event of a power outage, you can use this heater as
your primary heat source for the duration of the outage.
WARNING: A qualifi ed service person must install
heater. Follow all local codes.
CHECK GAS TYPE
Use only natural gas. If your gas supply is not natural
gas, do not install heater. Call dealer where you bought
heater for proper type heater.
THIS INSTALLATION REQUIRES:
Before installing heater, make sure you have the items
listed below:
• Piping (check local codes)
• Sealant (resistant to natural gas)
• Equipment shutoff valve*
• Ground joint union
• Test gauge connection*
• Sediment trap
• Tee joint
• Pipe wrench
Loading...