Maintenance; Troubleshooting; Rear - Mr. Heater BIG Buddy MH18B Operating Instructions And Owner's Manual

children, and must not be stored in a building, garage or
any other enclosed area.
•
Indoor storage of the heater is permissible only if the
cylinder is disconnected and removed from the heater.
Cylinders must be stored outdoors out of the reach of
children and must not be stored in a building, garage or
any other enclosed area.

MAINTENANCE:

Always keep the heater area clear and free from combustible
materials, gasoline and other flammable vapors and liquids.
Keep the vent areas (slots in the bottom and the top at the front
of heater) clear at all times.
Visually inspect the pilot flame and burner periodically during use.
The pilot flame should be blue in color (not yellow) and will extend
beyond the thermocouple. The flame will surround the
thermocouple just below the tip, see Figure 3. A slight yellow
flame may occur where the pilot flame and main burner flame
meet. The burner(s) should be bright orange (with a slight blue
color around the border, a red-orange haze that is visible on the
ceramic tile is acceptable) and without a noticeable flame. A blue
flame that rolls out at the top of the ceramic tile indicates an
Figure 3
accumulation of dust, lint or spider webs inside the casing
assembly and main burner assembly. If the pilot is yellow or the
burner has a noticeable flame, cleaning may be required. Use the
following procedure to inspect the casing assembly and main
burner assembly.
It is necessary to periodically check the burner(s) orifice and burner
venturi tube to make sure they are clear of insects/nests or spider
webs that may accumulate over time. A clogged tube can lead to
a fire.
1 Allow heater to thoroughly cool before performing any
maintenance.
2 Remove disposable 1 lb. cylinder(s) from heater or turn
OFF gas supply at remote cylinder valve, and disconnect
hose from heater.
3 Remove wire guard from front of heater by gently
bending to remove from holes in front cover.
4 Remove (4) screws securing back cover to heater. Lift up
slightly to release (2) plastic hooks on top of back cover.
5 Remove back cover.
Mr. Heater | Big Buddy/Tough Buddy
6 Remove (3) screws attaching lower baffle to expose
burner air openings.
7 Inspect interior of casing assembly for accumulation of
dust, lint or spider webs. If necessary, clean interior of
casing assembly with a vacuum cleaner or apply air
pressure (max. 30 psi). Do not damage any components
within casing assembly when you are cleaning.
8 Inspect and clean main burner orifice located at bottom
of burner venturi tube, by using a vacuum or apply air
pressure at orifice opening.
9 Inspect and clean pilot (mounted to bracket) by using a
vacuum or apply air pressure through the holes in the
pilot indicated by the arrows in Figure 3.
WARNING: Never use needles, wires, or similar cylindri-
cal objects to clean the pilot to avoid damaging the
calibrated ruby that controls the gas flow.
10 Apply air pressure (max. 30 psi) into ceramic tile of
burner(s) assembly and the venturi tube (with [2] air
openings) to remove dust, lint or spider webs.
11 Reinstall lower baffle with (3) screws
12 Slide back cover over (2) plastic hooks on top of heater.
Make sure rear cover aligns with plastic side covers.
Install (4) screws to hold in place.
TROUBLESHOOTING INFORMATION:
If Spark electrode does not produce spark.
CHECK
• Spark electrode broken – replace.
• Igniter wire may not be attached to spark electrode –
attach.
• Igniter wire damaged – replace.
• Piezo igniter on control valve defective – replace control
valve.
If Spark electrode produces spark but pilot does not light.
CHECK
• No gas to heater – install disposable cylinder or connect
hose and fuel filter then turn on valve at remote cylinder.
• "PILOT" position not properly aligned – turn gas control
knob to "PILOT" position and depress.
• Pilot is blocked from spider web or dirt – clean pilot, see
MAINTENANCE.
If Pilot flame does not stay lit when knob is released.
CHECK
• Control knob in "PILOT" position not completely
depressed or held in long enough to purge air from lines.
• Pilot flame not surrounding thermocouple – clean pilot,
see MAINTENANCE.
• Pilot Assembly defective – replace.
Tip switch wires disconnected – connect.
•
If Main burner(s) does not ignite.
CHECK
• Main burner(s) orifice is blocked – clean burner(s), see
MAINTENANCE.
If Heater keeps shutting "OFF" during normal operation.
CHECK
• Pilot is blocked – clean pilot, see MAINTENANCE.
• Provide minimum fresh air opening of 18 square inches
(example 4 1/4" x 4 1/4" opening
• Tip over switch activated from bumping heater. Re-light
7
Operating Instructions and Owner's Manual
).
05/06 78438CAL Rev. L1