United States Stove GW7400, Manual, Page: 17 / 44

-17-
Trouble Shooting
Problem: Possible Causes:
Extinguished Flame On Low Burn
Poor or lack of adequate draft.
Air leaks in the upper burn chamber
Too large of gap in upper chamber air wash (should be 0.08”)
Air leaks between the upper and lower burn chambers
Partially blocked primary burn grate
Partially blocked secondary air ports
Block in primary air
Extinguished Flame On High Burn
Block or inadequate gap in upper chamber air wash.
Excessive continuous draft > 0.1 inches of water column. (NEEDS VERIFIED)
Block in primary air
Dirty Glass Or Visible Smoke
Blocked primary burn grate
Extinguished flame on low or high burn
Inadequate draft
Fuel Flap Fails To Latch Open
Bi-metal switch or mounting bracket is bent
Bi-matelic strip is still too warm to reset the flap.
Fuel Flap Fails To Close When All Fuel Is
Consumed
Bi-metal switch installed upside down
Bi-metal switch or mounting bracket is bent
Movement of the counter weight is restricted by the reset handle
Pellet or other obstruction physically blocking plate from moving
Significantly Uneven Burn Across The
Opening
Leak in the secondary air chamber cover plate, inspect plate for damage or
blocked air ports.
Leak in the lower chamber to the upper chamber, this will cause flames
that are not burning primarily vertically or an outside flame that wanders
significantly to one side. Contact dealer for assistance on repairing.
Possible leaks around the fire pot. Visually inspect for damage or large
cracks in the fire pot.
Leak in the upper burn chamber
Excessive Pellets Dropping To The Burn
Basket
Damaged / significantly warped burn grate
Damaged / significantly warped secondary burn chamber cover plate.
Use of non PFI certified premium wood pellets – poor quality fuel.
Burn plate not adjusted properly.
Loud Rumbling
Lower burn chamber door open
Large air leak in lower burn chamber
Significant imbalance in air from upper to lower burn chambers
Verify proper gap in upper chamber air wash (should be 0.08”)
Verify proper sealing of both upper and lower doors
Verify proper seal from upper to lower burn chamber
Verify proper seal of the fire pot to the unit
Unable To Achieve A Low Burn
Leak in the lower burn chamber allowing too much primary combustion air
in.
Bent or damaged primary burn control lever
Too much draft <= 0.03
Leak in the gasket around the access door
Unable To Reach High Burn
Too little draft
Blockage in primary air inlet
Dirty primary burn grate or secondary air ports, inspect and clean if needed.
Excessive build up of ash could be causing bridging of the fuel or restricted
air flow.
Blockage or resistance in exhaust path
Verify proper installation of chimney to assure there are no air leaks or
blockages.
Possible leak around the upper door, inspect gasket, and replace if
necessary.
Air Wash gap in the upper door is too large (should be 0.08”)
Too High Of A High Burn Too much draft – Also results in visible smoke during high burn