Monessen Hearth DFX24C User Manual

Page of 36
33D4047
7
DFX & DBX Series Vent Free Fireplaces
TROUBLESHOOTING
W
ARNING
If the gas quality is bad, your pilot may not stay lit, the burners may 
produce soot and the heater may backfire when lit. If the gas quality 
or pressure is low, contact your local gas supplier immediately. 
OBSERVED PROBLEM
ODS/pilot  lights,  but  flame 
goes out when control knob is 
released.
Burner does not light after ODS/
pilot is lit.
Burner  backfires  during  com-
bustion.
Slight  smoke  or  odor  during 
initial operation.
Logs  appear  to  smoke  after 
initial operation.
Heater  produces  a  whistling 
noise when burner is lit.
No gas to pilot. 
POSSIBLE CAUSE
1.  Control knob not fully pressed in.
.  Control  knob  not  pressed  in  long 
enough.
3.  Manual shutoff valve not fully open.
4.  Thermocouple connection loose at control 
valve.
5.  Pilot  flame  not  touching  thermocouple, 
which allows thermocouple to cool, caus-
ing pilot flame to go out. This problem could 
be caused by either low gas pressure, or a 
dirty or partially clogged ODS/pilot.
6.  Thermocouple damaged.
7.  Control valve damaged.
1.  Burner orifice is clogged.
.  Burner orifice diameter is too small.
3.  Inlet gas pressure is too low.
1.  Manifold pressure is too low.
.  Burner orifice is clogged.
1.  Burner orifice is clogged or damaged.
.  Burner is damaged.
3.  Gas regulator defective.
1.  Vapors from paint or curing process of logs.
.  Vapors  or  smoke  continue  after  heater 
has run with damper or window open for 
several hours.
1.  Turning  control  knob  to  HIGH  position 
when burner is cold.
.  Air in gas line.
3.  Dirty or partially clogged burner orifices.
1.  LP-regulator shut down due to inlet pres-
sure too high.
REMEDY
1.  Press in control knob fully.
.  After ODS/pilot lights, keep control 
knob pressed in for 30 seconds.
3.  Fully open manual shutoff valve.
4.  Hand tighten thermocouple connec-
tion until snug, then tighten 1/4 turn 
more.
5a.Contact local gas company.
5b.Clean pilot with vacuum cleaner. 
6.  Replace thermocouple.
7.  Replace control valve.
1.  Clean orifice.
.  Replace burner orifice.
3.  Contact qualified service person.
1.  Contact local gas company.
.  Clean  burner  or  replace  burner  ori-
fice.
1.  Clean  burner  or  replace  burner  ori-
fice.
.  Replace burner.
3.  Replace gas regulator.
1.  Problem will stop after a few hours 
of  operation.  Run  the  heater  with 
the  damper  open  if  you  have  one, 
or  open  a  window  for  the  first  few 
hours.
.  Log heater is intended to be smoke-
less. Turn OFF heater and call quali-
fied service person.
1.  Turn  control  knob  to  LOW  position 
and let warm up for a minute.
.  Operate burner until air is removed 
from line. Have gas line checked by 
local gas company.
3.  Clean  burner  or  replace  burner  ori-
fice.
1.  Verify LP tank regulator is installed 
and set at 11" to 13" w.c.
.  Replace regulator on heater.