3
Operating Instructions and Owner’s Manual
Mr. Heater | Unvented Natural Gas Fired Room Heater
Specifications
MODEL
MHVFRD20NG
MHVFRD30NG
Input Rates
20,000 BTU/HR High/ 12,500 BTU/HR Low
30,000 BTU/HR High/ 20,000 BTU/HR Low
Type of Gas
Natural Gas Only
Natural Gas Only
Ignition
Piezo
Piezo
Manifold Pressure
4.5 Inches of Water
4.5 Inches of Water
Inlet Gas Pressure (Maximum) 14 Inches of Water
14 Inches of Water
Inlet Gas Pressure (Minimum)
7 Inches of Water
7 Inches of Water
Thermostatic Control
No
No
Clearances: Inches (mm)
Top
36” (91.4 cm)
36” (91.4 cm)
Sides
10” (25.4 cm)
10” (25.4 cm)
Floor (min. to top of carpet) 3” (7.6 cm)
3” (7.6 cm)
Fabric / flammable objects
36” (91.4 cm)
36” (91.4 cm)
CONTENTS
2
Warnings
3
Specifications
3
Precautions
4
Installation
9
Operation
Lighting
Shutdown
10
Maintenance
11
Troubleshooting
14
Parts List
16
Ordering Parts/Warranty
NEVER LEAVE THE HEATER UNATTENDED WHILE BURNING!
NEVER LEAVE THE HEATER UNATTENDED WHILE BURNING!
NEVER LEAVE THE HEATER UNATTENDED WHILE BURNING!
PRECA
UTIONS
PRECAUTIONS:
1. An unvented room heater having an
input rating of more than 10,000 BTU
(2931 W) (i.e. the MHVFRD20NG,
MHVFRD30NG) shall 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,
page 5.
3. Keep all air openings in heater clear,
free of debris or any blockage. This
will ensure 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 let cool before servicing.
Only a qualified service person should
service and repair heater.
6. Do not run heater:
• Where flammable 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
qualified 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.
Carbon Monoxide Poisoning:
Early signs of carbon monoxide poisoning
resemble the flu, 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 influence of alcohol, and
those at high altitudes.
**Operating heater above elevations of 4,500 feet could cause pilot/ODS to shutdown heater.**
DANGER: C
arbon monoxide
poisoning may lead to death.
SOCIAL MEDIA
In order to provide the best service possible Mr. Heater is now giving you more
ways to get in touch with us:
WEBSITE: Mr. Heater’s 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.
