22
Clean Outside Coil (Qualified Servicer Only)
The coil with the outside air flowing over it should be
inspected annually and cleaned as frequently as necessary
to keep the finned areas free of lint, hair and debris.
Condenser, Evaporator, and Induced Draft Motors
Bearings on the air circulating blower motor, condenser
motor and the combustion fan motor are permanently
lubricated. No additional oiling is required.
Flame Sensor (Qualified Servicer Only)
A drop in the flame current can be caused by a nearly
invisible coating on the flame sensor. This coating, created
by the fuel or combustion air supply, can be removed by
carefully cleaning the flame sensor with steel wool.
NOTE: After cleaning, the microamp signal should
be stable and in the range of 5-10 microamps DC.
Flue Passages (Qualified Servicer Only)
At the start of each heating season, inspect and, if
necessary, clean the unit flue passage.
Cleaning Flue Passages (Qualified Servicer Only)
1.
Shut off electric power and gas supply to the unit.
2. Remove burner assembly by disconnecting the gas
line and removing the manifold bracket from the
partition panel.
3.
Remove the flue from the induced draft blower and the
collector box cover from the partition panel.
4. The primary heat exchanger tubes can be cleaned
using a round wire brush attached to a length of high
grade stainless steel cable, such as drain cleanout
cable. Attach a variable speed reversible drill to the
other end of the spring cable. Slowly rotate the cable
with the drill and insert it into one of the primary heat
exchanger tubes. While reversing the drill, work the
cable in and out several times to obtain sufficient
cleaning. Use a large cable for the large tube, and
then repeat the operation with a small cable for the
smaller tube. Repeat for each tube.
5. When all heat exchanger tubes have been cleaned,
replace the parts in the reverse order in which they
were removed.
6. To reduce the chances of repeated fouling of the
heat exchanger, perform the steps listed in “Startup,
Adjustments, and Checks”.
Burners
WARNING
To avoid personal injury or death due to electric shock, do
not remove any internal compartment covers or attempt
any adjustment. Contact a qualified servicer at once if an
abnormal flame should develop.
The Ultra low NOx models are equipped with premix
burner. The burner box is sealed to achieve safe and
reliable operation. The burner box should not have any
blockage near the air-gas mixer inlet.
CAUTION
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dangerous
operation.
CAUTION
Always verify proper operation after servicing.
For further information on the yearly inspection, consult the
User Manual. It is recommended that a qualified servicer
inspect and service the unit at least once each year.
Turn the unit on at the thermostat. Wait a few minutes,
since any dislodged dust will alter the normal flame
appearance. Flames should be predominantly blue and
directed into the tubes. They should not be yellow. They
should extend directly outward from the burner ports
without curling downward, floating or lifting off the ports.
