Mr. Heater MHVFR30TB NG, MHVFR20TB LP, MHVFB20TB LP, MHVFR30TB LP, MHVFB30TB LP Operating Instructions And Owner's Manual

Installer: Leave this manual with the appliance. Consumer: Retain this manual for future reference.

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.

For model serial numbers,
see page 20.

Plaque Heaters

MHVFR20TB NG

MHVFR30TB NG

Blue Flame Heaters

MHVFB20TB NG

MHVFB30TB NG

UNVENTED NATURAL GAS FIRED ROOM HEATER

WARNING: If the information in this manual is not followed exactly, a re or explosion may result causing

property damage, personal injury, or loss of life.

- Do not store or use gasoline or other 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 re department.

- Installation and service must be performed by a qualied installer, service agency, or the gas supplier.

WARNING: This is an unvented gas-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 qualied installer, service agency, or gas supplier.

MR. HEATER, INC., 4560 W. 160TH ST., CLEVELAND, OHIO 44135 · 800-251-0001

04/13 70808 Rev13A

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.

*Aftermarket completion of sale, not for the purpose of resale, from the manufacturer.

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, re,
explosion, electrical shock, and carbon monoxide
poisoning.

WARNING: This appliance is equipped for (natural
or propane) 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 ammable
material on or near the appliance. Never place
any objects on the heater.

• Due to high temperatures, heater should be
kept out of traf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
ammable vapors and liquids.

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

Unvented Natural Gas Vent Free Room Heaters

Installation Instructions and Owner’s Manual

2

SPECIFICATIONS

IR20TB NG IR30TB NG BF20TB NG BF30TB 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 5.0 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

Burners / Orice nozzles 3 4 1 1

Thermostatic Control Yes Yes Yes Yes

Clearances: inches (mm)

Top 36” (915cm) 36” (915cm) 36” (915cm) 36” (915cm)

Sides 10.5” (267cm) 10.5” (267cm) 10.5” (267cm) 10.5” (267cm)

Floor (min to top of carpet) 2” (51cm) 2” (51cm) 2” (51cm) 2” (51cm)

Fabric / ammable objects 36” (915cm) 36” (915cm) 36” (915cm) 36” (915cm)

120V, 60Hz , 1

120V, 60Hz , 1 120V, 60Hz , 1 120V, 60Hz , 1

PRECAUTIONS:

1. BF-20 NGT, BF-30 NGT, IR-20 NGT and IR-30 NGT
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 qualied service person should
service and repair heater.

6. Do not run heater:

• Where 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 quali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.

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
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 in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.

Unvented Natural Gas Vent Free Room Heaters

Installation Instructions and Owner’s Manual

3

Product Features

Fan Blower
Switch

(located on back of
heater)

Burners

Ignitor Button

Control Knob

FRESH AIR FOR COMBUSTION AND
VENTILATION

WARNING: This heater shall not be installed in a

con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.

Grill

Heater
Cabinet

Front Panel

Figure 1

SAFETY DEVICE

This heater has a pilot with an Oxygen Depletion Sen­sor (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

These heaters also include an electrical blower. The
blower switch has three positions: MANUAL, OFF and
AUTO. 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.

ESTABLISHING 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 classications:

1. Unusually Tight Construction

2. Unconned Space

3. Conned Space

This heater must not be installed in a conned space or
unusually tight construction unless provisions are pro­vided 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 Ventilation Air
from Outdoors, page 6.

Unusually tight construction is de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-m2) or

less with openings gasketed or sealed and

b. Weather stripping has been added on openable win-

dows 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 Determing the Type of Heater Location
Space, page 5.

Conned Space and Unconned Space

The National Fuel Gas Code, NFPA 54/ ANSI Z223.1

denes a conned space as a space whose volume is
less than 50 cubic feet per 1,000 Btu per hour (4.8 m3
per kW) of the aggregate input rating of all appliances
installed in that space, and an unconned space as a
space whose volume is not less than 50 cubic feet per
1,000 Btu per hour (4.8 m3 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 uncon­ned space.

Unvented Natural Gas Vent Free Room Heaters

Installation Instructions and Owner’s Manual

4

*Adjoining rooms are communication only if there
are doorless passageways or ventilation grills be­tween them.

DETERMINING THE TYPE OF HEATER
LOCATION SPACE:

Use this method to determine if you have a conned or
uncon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: If the area in which the heater may be
operated is smaller than dened as an unconned
space or if the building is of unusually tight con­struction, provide adequate combustion and ventila­tion air by the methods described in the National

Fuel Gas Code, NFPA 54/ ANSI Z223.1, Section

5.3 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 re­place logs, and Other gas appliances*

*Do not include direct-vent gas appliances. Direct­vent 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 con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 unconned
space, remove door to adjoining room or add venti­lation grills between the rooms. See Ventilation Air

Unvented Natural Gas Vent Free Room Heaters

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 unconned.

If actual Btu/hr used is less than the maximum Btu/
hr the space can support, the space is an uncon­ned space. You will need no additional fresh air
ventilation.

VENTILATION AIR

Ventilation from Inside Building

This fresh air would come from an adjoining unconned
space. When ventilation to an adjoining unconned
space, you must provide two permanent openings: one
within 12” of the ceiling and one within 12” of the oor
on the wall connecting the two spaces (see options 1
& 2 of g. 2). You can also remove door into adjoin­ing room (see option3, 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 ventila­tion grills or ducts.

12”

Ventilation
Gills into
Adjoining
Room ­Option 1

Or remove
door into
Adjoining
Room ­Option 3

Ventilation Gills into
Adjoining Room - Option 2

12”

Figure 2.

VENTILATION AIR

OUTLET AIR

OUTLET

AIR

INLET

AIR

VENTILATION CRAWL SPACE

VENTILATED

ATTIC

TO CRAWL
SPACE

Figure 3.

Installation Instructions and Owner’s Manual

5

TO ATTIC