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clean
recovery cylinder and the recovery machine
according to the instructions provided with the recov-
ery machine. Remove all R22 refrigerant from the ex-
isting system. Refer to gauges after shutdown to con-
firm that the entire system is completely void of refrig-
erant. Disconnect the liquid and vapor lines from the
existing outdoor unit.
If the existing outdoor unit is equipped with
manual shut−off valves AND you plan to use NEW
R22 refrigerant to flush the system
−
Start the exist-
ing R22 system in the cooling mode and close the liq-
uid line valve. Pump all of the existing R22 refrigerant
back into the outdoor unit. (It may be necessary to by-
pass the low pressure switches to ensure complete
refrigerant evacuation.) When the low side system
pressures reach 0 psig, close the vapor line valve.
Disconnect all power to the existing outdoor unit. Re-
fer to gauges after shutdown to confirm that the
valves are not allowing refrigerant to flow back into
the low side of the system. Disconnect the liquid and
vapor lines from the existing outdoor unit.
2 − Remove the existing outdoor unit. Set the new R410A
unit and follow the brazing connection procedure
which begins on the previous page to make line set
connections.
DO NOT install the provided fixed ori-
fice yet.
Make low voltage and line voltage connections to the
new outdoor unit.
DO NOT turn on power to the unit
or open the outdoor unit service valves at this
time.
3 − Remove the existing refrigerant flow control orifice or
thermal expansion valve before continuing with flush-
ing procedures. The existing devices are not ap-
proved for use with R410A refrigerant and may pre-
vent proper flushing. Use a field−provided fitting to re-
connect the lines.
IMPORTANT
The line set and indoor coil must be flushed with at
least the same amount of clean refrigerant that pre-
viously charged the system. Check the charge in
the flushing cylinder before proceeding.
Flushing Connections
Low
Pressure
High
Pressure
Vapor Line
Service Valve
Indoor Coil
HSXA12
Unit
GAUGE MANIFOLD
RECOVERY MACHINE
Inverted R22 Cylinder
(Contains clean R22 to
be used for flushing)
Liquid Line
Service Valve
Inlet
Discharge
Tank Return
Closed
Opened
Existing
Existing Vapor Line
Existing Liquid Line
RECOVERY CYLINDER
NOTE − The inverted R22 cylin-
der must contain at least the
same amount of refrigerant as
was recovered from the existing
system.
Figure 9
