MUA-SVX01A-EN • Direct-Fired Make-up Air
57
Maintenance
Heater
At least a yearly inspection is recommended for heating installations and more
frequently for process applications in year-round operation. Experience is the
best guide in determining frequency of inspection, but as a minimum, the
following procedure should be followed.
WARNING
Hazardous Voltage!
Disconnect all electric power, including remote disconnects and discharge all
motor start/run capacitors before servicing. Follow proper lockout/tagout
procedures to ensure the power can not be inadvertently energized. Failure to
disconnect power before servicing could result in death or serious injury.
WARNING
Combustible
Materials!
Maintain proper clearance between the unit heat exchanger, vent surfaces and
combustible materials. Refer to unit nameplate and installation instructions for
proper clearances. Improper clearances could result in a fire hazard. Failure to
maintain proper clearances could result in death or serious injury or property
damage.
1.
Shut the system down totally, disconnecting or locking out power supply.
2.
Inspect the burner carefully, including upstream and downstream sides of
mixing plates as well as burner body face.
Note: The complete burner assembly may have to be removed for proper
inspection and cleaning. Any accumulation of scale or foreign material on
either side of the mixing plates should be removed with a wire brush.
Visually check that no holes in the mixing plates are blocked. If burner
ports are plugged (even partially) clear with a piece of wire. See
maintenance of gas ports.
CAUTION
Equipment
Damage!
Do not enlarge burner ports, doing so may drastically affect equipment
performance.
3.
If any mixing plates are loose or missing fasteners, tighten/replace as
necessary. Always use zinc plated or stainless fasteners
Note: The missing plates on the burner may display hairline cracks. These cracks
are normal and caused by thermal stresses occurring during combustion.
The presence of these hairline cracks in no significant way affects the
combustion efficiency or performance of the heater. Should a large
opening develop, the specific mixing plate or plates must be replaced.
Otherwise, it may cause difficulties in cross ignition of flame across the
face of the burner.
4.
Place the system back into operation and view burner while cycling through
full firing range. This will give a visual check for blocked burner spots.
5.
Inspect the flame rod and ignition electrode for dirt and moisture. Wipe off if
necessary. Examine for any evidence of premature arcing. If in doubt, check
continuity of flame rod to be sure it is not grounding out. Replace if required.
6.
The porcelain on the ignition electrode must be intact (not cracked). The
spark gap should be between 1/16 and 3/32 of an inch on Maxon™ burners
and 1/8 of an inch on Mestek™ burners.
