Maintenance; Troubleshooting - Mr. Heater MH9BX Operating Instructions And Owner's Manual

MaInTenanCe:

Always keep the heater area clear and free from combus-
tible materials, gasoline and other flammable vapors and
liquids.
Keep­the­vent­areas­
(slots in the bottom
and the top at the
front­of­heater)­
clear at all times.
Visually­inspect­the­
pilot flame and
burner periodically
during use. The
pilot flame should
be blue in color
Figure 5
(not­yellow)­and­will­extend­beyond­the­thermocouple.­The­
flame will surround the thermocouple just below the tip,
see Figure 5.
A slight yellow flame may occur where the pilot flame
and main burner flame meet. The burner should be bright
orange (with a slight blue color around the border, a red-
orange­haze­that­is­visible­on­the­ceramic­tile­is­acceptable)­
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
has­a­noticeable­flame,­cleaning­may­be­required.­Use­the­
following procedure to inspect the casing assembly and
main burner assembly.
It is necessary to periodically check the burner 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 from heater or turn
OFF gas supply at remote cylinder valve, and disconnect
hose from heater.
3­ Remove­(4)­four­screws­that­secure­the­rear­cover­to­the­
Heater.
4 Pivot cover outward from bottom. Release from 2 top
clips. Set aside.
5­ Remove­(4)­four­burner­retaining­screws­and­fuel­line­
from burner assembly. Remove burner assembly from
back of housing.
6 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. Do not damage any components within casing
assembly when you are cleaning.
7 Inspect and clean main burner orifice (threaded into
orifice­holder).­Orifice­holder­is­attached­to­the­burner­
assembly­venturi­with­(2)­two­screws.
8­ Inspect­and­clean­pilot­(mounted­to­bracket)­by­using­a­
Mr. Heater | Portable Propane Heater
vacuum or apply air pressure through the holes in the
pilot indicated by the arrows in Figure 5.
warnInG: Never use needles, wires, or similar cylin-
drical objects to clean the pilot to avoid damaging the
calibrated orifice that controls the gas flow.
9­ Apply­air­pressure­(max.­30­psi.)­into­ceramic­tile­of­
burner­assembly­and­the­venturi­tube­(ref.­item­#16)­to­
remove dust, lint or spider webs.
10 Reassemble main burner orifice holder onto the burner
assembly.
11 Reinstall burner assembly into the heater housing
12 Reinstall fuel line and check for leaks.
13 Install heater back cover.
TrOuBlesHOOTInG InFOrMaTIOn:
If Spark electrode does not produce spark.
CHECK
•­Spark­electrode­broken­–­replace­ODS­(Oxygen­Depletion­­­
­­­Sensor).
•­Igniter­wire­may­not­be­attached­to­spark­electrode,­­­
ground wire may not be attached to frame - attach.
•­Igniter­wire­damaged­–­replace.
•­Piezo­igniter­defective­–­replace.
If Spark electrode produces spark but pilot does not light.
CHECK
•­No­gas­to­heater­–­install­disposable­cylinder­or­connect­­
hose and turn on valve at remote cylinder.
•­"PILOT"­position­not­properly­aligned­–­turn­gas­control­
­­­knob­to­"PILOT"­position­and­depress.
•­Pilot­is­blocked­from­spider­web­or­dirt­–­clean­pilot,­see­­­
MAINTENANCE.
If Pilot flame does not stay lit when knob is released.
CHECK
•­Control­knob­in­"PILOT"­position­not­completely­­
depressed or held in long enough to purge air from lines.
•­Pilot­flame­not­surrounding­thermocouple­–­clean­pilot,­
see MAINTENANCE.
•­Pilot­Assembly­defective­–­replace.
•
Tip­switch­wires­disconnected­–­connect.
If Main burner does not ignite.
CHECK
•­Main­burner­orifice­is­blocked­–­clean­burner,­see­
MAINTENANCE.
If Heater keeps shutting "OFF" during normal operation.
CHECK
•­Pilot­is­blocked­–­clean­pilot,­see­MAINTENANCE.
•­Provide­minimum­fresh­air­opening­of­9­square­inches­
­­­(example­3"­x­3"­opening).
•­Tip­over­switch­activated­from­bumping­heater.­Re-light
•­Regulator­defective­-­Replace­regulator.
•­Internal­contamination­-­Replace­control­valve­and­
regulator.
•­Call­Technical­Services­for­additional­information.
6
Operating Instructions and Owner's Manual