Troubleshooting - Mr. Heater MHVFRD10NG Operating Instructions And Owner's Manual

TROUBLESHOOTING

NOTE: All troubleshooting items are listed in order of operation and likely occurrence.
WARNING: Only a qualifi ed service person should service and repair heater.
CAUTION: Never use a wire needle, or similar object to clean ODS/pilot. This can damage ODS/pilot unit.
Make sure grille guard is in place before running heater. If screen or grille guard is removed for servicing it must be
replaced prior to operating the heater.
WARNING: If you smell gas:
•
Shut off gas supply
•
Do not try to light any appliance
•
Do not touch any electrical switch; do not use any phone in your building
•
Immediately call you gas supplier from a neighbor's phone. Follow the gas supplier's instructions.
•
If you cannot reach your gas supplier, call the fi re department.
IMPORTANT: Operating heater where impurities in air exist may create odors. Cleaning supplies, paint, paint remov-
er, cigarette smoke, cements and glues, new carpet or textiles, etc., create fumes. These fumes may mix with com-
bustion air and create odors and possible discoloration of walls and ceilings.
OBSERVED SYMPTOM
When ignitor button is pressed in,
there is a spark at the ODS/pilot but no
ignition
Burner does not light after ODS/pilot
is lit
Delayed ignition of burner
Burner backfi ring during operation
Burner plaque(s) does not glow [Infra-
red Only]
Slight smoke or odor during initial
operation
Heater produces a whistling noise when
burner is lit
Unvented Natural Gas Fired Room Heater
POSSIBLE CAUSE
1. Control knob not fully pressed in.
2. Control knob not pressed in long enough
3. Equipment shutoff valve not fully open
4. Thermocouple connection loose at control valve
5. Pilot fl ame not touching thermocouple, which
allows thermocouple to cool, causing pilot fl ame
to go out. This problem could be caused by one
or both of the following:
a. Low gas pressure
b. Dirty or partially clogged ODS/pilot
6. Thermocouple damaged
7. Control valve damaged
1. Burner orifi ce is clogged
2. Burner orifi ce diameter to small
3. Inlet gas pressure is too low
1. Manifold pressure is too low
2. Burner orifi ce is clogged
1. Burner orifi ce is clogged or damaged
2. Burner damaged
3. Gas regulator defective
1. Plaque damaged
2. Control knob set between locked positions.
3. Inlet gas pressure is too low
1. Residues from manufacturing process
1. Turning control knob to HI position when burner
is cold
2. Air in gas line
3. Air passageways on heater blocked
4. Dirty or partially clogged burner orifi ce.
12
REMEDY
1. Press in control knob fully
2. After ODS/pilot lights, keep control knob
pressed in for 30 seconds
3. Fully open equipment shutoff valve
4. Hand tighten thermocouple nut until snug, and
then tighten 1/4 turn more.
5. -
a. Contact local gas company
b. Clean ODS/pilot (see Cleaning and
Maintenance, page 11).
6. Replace thermocouple
7. Replace Control valve.
1. Clean burner orifi ce (see Cleaning and
Maintenance on page 11), or replace burner
orifi ce
2. Replace burner orifi ce
3. Contact local gas company
1. Contact local gas company
2. Clean burner orifi ce (see Cleaning and
Maintenance on page 11), or replace burner
orifi ce
1. Clean burner orifi ce (see Cleaning and Main-
tenance on page 11), or replace burner orifi ce
2. Replace burner
3. Replace gas regulator
1. Replace burner
2. Turn control knob until it locks at desired set-
ting.
3. Replace gas regulator
1. Problem will stop after a few hours of opera-
tion
1. Turn control knob to LO position and let warm
up for a minute.
2. Operate burner until air is removed from line
have gas line checked by local gas company.
3. Observe minimum installation clearances (see
Figure 4 page6)
4. Clean burner orifi ce (see Cleaning and Main-
tenance on page 11), or replace burner orifi ce.
Installation Instructions and Owner's Manual