Mldv series gas fireplace – Monessen Hearth DIRECT VENT MLDV500 User Manual
Page 54

54
75D0004
MLDV Series Gas Fireplace
TROUBLESHOOTING
STANDING PILOT IGNITION MILLIVOLT SYSTEM
SYMPTOM
POSSIBLE CAUSE
ACTION
4. Frequent pilot
outage problem.
5. The pilot and main
burner extinguish 
while in operation 
6. Glass Soots
7. Flame burn blue
and lifts off burner 
(ghosting)
A. Pilot flame may be too high
or too low, causing pilot 
safety to drop out 
A. Inner vent pipe leaking
exhaust gases back into 
system 
B. Horizontal vent improperly
pitched
C. Improper vent cap installa-
tion
A. Flame impingement on logs
A. Insufficient oxygen being
supplied
A. Clean and adjust the pilot flame for maximum flame
impingement on thermocouple.
A. Check for flue product leak. Replace defective pipe sec-
tion.
B. Check horizontal-venting piping is running upward 1/4"
per foot. Do not run the pipe level or downward.
C. Check for proper installation and freedom from debris
or blockage.
A. Install log set per the instructions 
 Inspect the injector and air intake area. Make sure 
this area does not have any blockage from debris and 
clean. 
Check gas supply.
A. Ensure that the vent cap is installed properly and free of
debris. Ensure that the vent system joints are tight and 
have no leaks. Ensure that no debris has been blocking 
the inner air intake at the bottom back of the combustion 
chamber. Ensure that the glass is properly secure and 
latch.
