GSZH5 Service Manual
104
SERVICING
Two Piece Air Handler External Static Pressure
1. Using a Inclined Manometer or Magnehelic gauge,
measure the static pressure between the outlet of the
evaporator coil and the inlet of the air handler, this will
be a negative pressure (For Example: .30” wc).
2. Measure the static pressure of the supply duct at the
outlet of the unit, this should be a positive pressure
(For Example: .20” wc).
3. Add the two readings together (For Example: .30” wc +
.20” wc = .50” wc total static pressure).
read directly on the manometer if so desired.
4.
air (CFM) at the measured external static pressure.
Furnace External Static Pressure
1.
Manometer or Magnehelic gauge measure the static
pressure of the return duct at the inlet of the furnace
(Negative Pressure).
2. Measure the static pressure between the furnace and
the inlet of the evaporator coil (Positive Pressure). The
limit switch can be removed, and probe inserted to
obtain this reading.
3. Add the two (2) readings together for total external
static pressure.
read directly on the manometer if so desired. If high
conjunction with the furnace, the readings must also
include these components, as shown in the following
drawing.
4.
(CFM).
If the total external static pressure exceeds the minimum
or maximum allowable statics, check for closed dampers,
registers, undersized and/or oversized poorly laid out
ductwork.
Static Pressure Drop
Periodic Maintenance
Motors
Indoor and Outdoor motors are permanently lubricated and
do not need additional oiling.
Cleaning Outdoor Coil
1. Check for oil deposits on coil this could be an indication
of possible leak. If no leak detected spray coil with
ordinary household detergent.
2. Using garden hose, spray coil vertically downward with
constant stream of water at moderate pressure. Keep
nozzle at a 15 to 20° angle, about 3 in. from coil face.
Spray so debris is washed out of coil and base pan.
3. Reinstall top cover and position blade.
4. Reconnect electrical power and check for proper
operation.
Cleaning Outdoor Fan Blade
1. Check balance weights on fan blade.
2. Check fan blade setscrew for tightness.
Electrical Controls and Wiring
1. Disconnect power to both outdoor and indoor units.
2. Check all electrical connections for tightness.
3. Tighten all screws on electrical connections.
4. Connections that appear to be burned or smoky should
be disassembled and cleaned all parts
5. Wire connections that appear burned and corroded
should be replaced and crimp tightly to assure they do
not overheat.
6. Reconnect electrical power to indoor and outdoor units
and check for proper operation.