Mr. Heater MHU 50 Operating Instructions And Owner's Manual page 15

Section 2 FUEL CONVERSION INSTRUCTIONS
Figure 1
Honeywell
WARNING: Explosion Hazard
Turn off the gas supply to the heater
before performing any service or
maintenance.
Failure to follow these instructions will
result in death, injury or property damage.
WARNING: Electrical Shock Hazard
Unplug the electrical cord from the outlet
before performing any service
maintenance.
Failure to follow these instructions will
result in death, injury or property damage.
The electrode and sensor are not adjustable.
DO NOT change location or position as part
of this conversion kit.
Step 1
CAUTION THE UNIT MUST NOT BE CONNECTED TO EITHER
THE GAS SUPPLY OR THE ELECTRICAL POWER SUPPLY,
BEFORE PROCEEDING WITH CONVERSION.
Step 2
Remove and retain the four screws holding the manifold on to
the burner box (Figure 1). Rotate the valve/ manifold assembly,
away from the burners (Figure 2). The valve/manifold assembly
holds the orifices (3-HSU/MHU50, 5-HSU/MHU80. This will allow
access to the orifices on the manifold, and also the adjustment
spring in the valve/regulator.
4 Screws
15
Compact Unit / Utility Heater
Step 3
Remove and discard the adjustment spring cap from gas valve/
regulator with a flat blade screw driver by turning the screw
counter-clockwise. Remove and discard the regulator adjustment
screw found under the cap. Remove and discard the spring that
is located under the adjustment screw. Take the spring kit from
the conversion kit, and compare the part number of the kit to
the parts list on page 3. If it does not match, immediately contact
Mr. Heater, Inc. for the correct kit. After confirming the spring
kit is correct for the heater model you are converting, install the
new spring and adjustment screw. Turn spring adjustment screw
clockwise (in) until the screw stops, then turn it counter-clockwise
(back) 1 ½ turns. Place conversion label supplied with the spring
kit on the valve near the adjustment screw cover opening.
Step 4
Remove and discard the orifices (3-HSU/MHU50, 5-HSU/MHU80)
from the manifold with using a ½ " open end wrench. Turn
them counter-clockwise to remove. Take the new orifices from
the conversion kit and before installing, confirm that the number
stamped on the side of the orifice matches the number for the kit
being installed. If it does not, immediately contact Mr. Heater,
Inc. for the correct kit. If they are the correct orifices, install them
in the manifold using caution not to cross thread.
Step 5
Rotate the valve/ manifold assembly back up into the burner box,
making sure that all the orifices are indexed into the burners and
are not caught on the locating ring on the back of each burner.
Secure the manifold to the burner box with the four screws
removed in step 2.
Step 6
Following the instructions in the unit heaters operations manual
mount the heater and connect the gas supply (making sure to
leak check all connections with soapy water).
Operating Instructions and Owner's Manual
Rotate Valve/
Manifold
Assembly