Mendota ML39 Assembly, Installation And Operating Instructions page 79

6.4 OVER FIRING OR UNDER FIRING OF BURNER
NEVER "over fire" or "under-fire" units by increasing or decreasing the main orifice sizes or by adjusting gas pressure to increase
BTUH above nameplate specifications.
Over firing can cause permanent damage to firebox and deterioration of parts and void the warranty.
Under-firing can potentially cause delayed ignition and lead to property loss and person injury and will void the warranty.
If you are using a "backyard" Natural Gas well as the gas source, you must submit formal gas analysis data
sheets to Mendota Fireplaces f or review and calculation of proper main burner orifice sizes prior to first
firing. It is known that unpurified Natural Gas from "backyard" wells can contain high energy levels causing
over firing. Further, unpurified gas can contain high levels of Sulphur and other compounds which can
damage the burner materials and the ceramic glass. Use of unpurified gas will void the warranty for this
product.
6.5 BURNER FLAME HEIGHTS REFERENCE DIAGRAM
Figure 6-2 Burner Flame Heights: This image provides a visual reference for the burner flames
burning at maximum height after the burners have been operating for 30 minutes or longer.
This, however, is dependent on the gas type, air shutter opening setting and vent system
configuration. Actual flame heights can be slightly higher or lower when compared to this
reference image.
85-03-01136 ML39 Page 79