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

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 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
Figure 3
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 bend-
ing 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.
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
9 Inspect and clean pilot (mounted to bracket) by using a
10 Apply air pressure (max. 30 psi) into ceramic tile of
1 1 Reinstall lower baffle with (3) screws
12 Slide back cover over (2) plastic hooks on top of heater.

trOuBlesHOOting inFOrMatiOn:

If Spark electrode does not produce spark.
If Spark electrode produces spark but pilot does not light.
If Pilot flame does not stay lit when knob is released.
If Main burner(s) does not ignite.
If Heater keeps shutting "OFF" during normal operation.
7
Mr. Heater | Big Buddy Operating Instructions and Owner's Manual
of burner venturi tube, by using a vacuum or apply air
pressure at orifice opening.
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 cylin-
drical objects to clean the pilot to avoid damaging the
calibrated ruby that controls the gas flow.
burner(s) assembly and the venturi tube (with [2] air
openings) to remove dust, lint or spider webs.
Make sure rear cover aligns with plastic side covers.
Install (4) screws to hold in place.
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.
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.
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.
CHECK
• Main burner(s) orifice is blocked – clean burner(s), see
MAINTENANCE.
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
).