5Operating Instructions and Owner’s ManualMr. Heater | Gas-Fired Infra-Red Portable Heater
1. GENERAL INFORMATION
A. The Mr. Heater MH12T and the MH12TS are high pressure
propane appliances and are designed to be connected to a bulk
propane tank. Every unit is tested during manufacturing and
shipped fully assembled except for bulk tank.
B. These heaters are equipped with an automatic Safety Shutoff
Valve. The gas flow will automatically stop if the heater fails to
operate for any reason.
C. Maximum safety and convenience have been built into the Hi-
Med-Lo-Off Control Valve/Regulator. The following table lists the
approximate BTU’s consumed and the operating hours you can
reasonably expect from bulk propane cylinders.
D. Model MH12TS is equipped with a “Sparklite” igniter for
convenient heater lite-off.
2. FOR SAFE OPERATION
A. READ INSTRUCTIONS CAREFULLY: Read and adhere to
these instructions. Do not allow anyone who has not read the
instructions to assemble, light, adjust or operate the heater.
WARNING

KEEP THE HEATER OUT OF THE REACH OF CHILDREN

B. PROPANE IS VERY FLAMMABLE: In the event of a leak,
propane will accumulate and the possibility of a fire is present.
Propane gas is scented and its strong odor is readily detectable.
spark in an enclosure when you smell propane gas. Ventilate the
area thoroughly, move the heater outside, find and correct the
source of the leak before attempting to light any appliance. If
you are unsure of these instructions evacuate immediately and
call for help.
C. GAS LEAKAGE: If the leak cannot be corrected do not tamper
with the heater, follow the shut down instructions and return
the heater to the dealer or address given on last page.
WARNING

DO NOT USE THIS HEATER ON BULK TANKS OF GREATER

CAPACITY THAN 20 POUNDS LPG (50 POUNDS WATER

CAPACITY).

D. LEAK DETECTION: Before each use of the heater check all
fittings and connections with a soap solution to be sure there
into the On-Off valve on the propane cylinder. NEVER, NEVER
USE ANY FLAME FOR LEAK TEST.
E. CONNECTING HEATER TO PROPANE CYLINDER: Always
connect the heater to the bulk cylinder in the outdoors or in
a well ventilated area. Use a 7/8” open end wrench. NEVER
connect this heater to a cylinder near an open flame.
F. USE OF HEATER: Always operate the heater with the propane
cylinder in an upright position on a level noncombustible surface.
NEVER place the cylinder on its side when operating the heater.
G. ATTEND HEATER: Do not leave heater unattended while it is in
operation.
H. ALWAYS LIGHT HEATER WITH MATCH OR “SPARKLITE”
IGNITER: NEVER attempt to light the heater with a spark lighter.
I. DO NOT TAMPER: Should the heater not perform properly,
such as little or no heat when operating in the “Hi” position, or
for any other reason, DO NOT ATTEMPT TO REPAIR OR TAMPER
with the heater. Any tampering could make the use of the heater
unsafe and dangerous. Return the heater to the dealer or the
address given on last page for repair or replacement.
J. FOR STORAGE: The heater Hi-Med-Lo-Off regulating valve
should always be turned to “off” when the heater is not in
use. Allow at least 15 minutes for cooling before handling and
storing. Detach propane cylinder from heater before storing. DO
NOT store propane cylinders near open flame or heat.
K. DO NOT TRANSPORT OR MOVE APPLIANCE WHILE IN
OPERATION OR WHILE HEATER IS ATTACHED. FOLLOW
SHUTDOWN AND STORAGE INSTRUCTIONS TO TRANSPORT
OR MOVE THIS APPLIANCE.
3. VENTILATION

A. WARNING: This heater is an unvented appliance and

MUST be used ONLY in a well ventilated area. NEVER

attempt to operate the heater inside any vehicle, camper or

enclosure.

B. FOR OUTDOOR USE ONLY. Any combustion process

requires and consumes oxygen, and will produce carbon

monoxide.

C. WARNING: provide ample ventilation. This heater con-

sumes air (oxygen). Do not use this heater in unventilated

structures to avoid endangering your life. Provide additional

ventilation for any additional fuel-burning appliances and

additional occupants.

4. MINIMUM CLEARANCE FROM COMBUSTIBLE MATERIALS
A. When operating, the heater surfaces are extremely hot. Keep
sleeping bags, clothing, and all combustible materials clear of the
heater by at least the distances shown in Figure 4.
B. WARNING: To avoid injury or property damage never allow
clothing, tents or other combustible materials within 30” of the
level when in use. Never operate the heater when sleeping.
C. WARNING: Never direct the heat output of this heater toward
any propane tank within 20 feet.
Valve Position BTU Input Cylinder 20 Lb.
Hi 14,000 30 hours
Med 12,000 35 hours
Lo 8,000 52 hours
Figure 3