Mr. Heater MHVFRD10NG Operating Instructions And Owner's Manual page 13

OBSERVED SYMPTOM
Heater produces a
whistling noise when
burner is lit
White powder residue
forming within burner box
or on adjacent walls or
furniture
Heater produces unwanted
odors.
Heater shuts off in use
(ODS operates)
Gas odor even when
control knob is in OFF
position
Gas odor during
combustion
Heater produces a clicking/
ticking noise just after
burner is lit or shut off
Moisture/condensation
noticed on windows
Unvented Natural Gas Fired Room Heater
POSSIBLE CAUSE
Turning control knob to HI position when
burner is cold
Air in gas line
Air passageways on heater blocked
Dirty or partially clogged burner orifice.
When heated, vapors from furniture
polish, wax, carpet cleaners, etc., turn
into white powder residue
Heater burning vapors from paint,
hair spray, glues, etc. See IMPORTANT
statement on page 12
Gas leak. See WARNING statement at
top of page 12
Not enough fresh air is available
Low line pressure
ODS/pilot is partially clogged
Gas leak. See WARNING statement at
top of page 12
Control valve is defective
Foreign matter between control valve
and burner
Gas leak. See WARNING statement at
top of page 12
Metal expanding while heating or
contracting while cooling
Not enough combustion/ventilation air
REMEDY
Turn control knob to LO position and let warm up for a minute
Operate burner until air is removed from line have gas line
checked by local gas company
Observe minimum installation clearances (see Figure 4 page 6)
Clean burner orifice (see Cleaning and Maintenance on page
11), or replace burner orifice
Turn heater off when using furniture polish, wax, carpet cleaner
or similar products
Ventilate room. Stop using odor-causing products while heater
is running
Locate and correct all leaks (see Checking Gas Connections,
page 9)
Open window and/or door for ventilation
Contact local gas company
Clean ODS/pilot (see Cleaning and Maintenance, page 1 1)
Locate and correct all leaks (see Checking Gas Connections,
page 9)
Replace control valve
Take apart gas tubing and remove foreign matter
Locate and correct all leaks (see Checking Gas Connections,
page 9)
This is common with most heaters. If noise is excessive, contact
qualified service person
Refer to Fresh Air for Combustion and Ventilation page 3
through 5
13
Installation Instructions and Owner's Manual