Heat Exchanger Replacement

Removal

Recover the refrigerant charge from the both refrigeration systems (see “Refrigerant Recovery” in this chapter).
Remove the panel that protects the heat exchanger assembly in the power cord storage compartment.
Heat and unsolder all system inlet and outlet line connections.
Remove the heat exchanger assembly from the unit.

Clean the tubes for soldering.
Place the heat exchanger assembly in the unit and position in refrigeration system tubing.
Solder all refrigerant line connections.

Note It is strongly recommended that dry nitrogen be used to purge the system during any solder operations (see “Using Pressurized Nitrogen” in this chapter).

Note If pressurizing with nitrogen, front seat the discharge valve to prevent nitrogen from entering the refrigerant charge.
- Equipment Damage
- Any time the discharge valve is front seated, disconnect the unit power source to prevent accidental compressor start-up.
Do one of the following:
- Pressurize the R-134a system on the low side and check for leaks
- Pressurize the R-23 system on the high side and check for leaks.
If no leaks are found, recover the leak test gas from both systems (see “Refrigerant Recovery” in this chapter).
Evacuate both systems (see “Evacuation and Cleanup of the Refrigeration System” in this chapter).
Recharge both refrigerant systems (see “Refrigerant Charge” in this chapter).