Lennox International Inc CONDENSING UNITS Flushing Line Set and Indoor Coil, Page

Flushing Line Set and Indoor Coil

Flushing is only required if existing indoor coil and line set are to be used. Otherwise proceed to Installing Indoor Metering Device on page 15.

TYPICAL EXISTING FIXED ORIFICE	TYPICAL EXISTING EXPANSION VALVE REMOVAL
REMOVAL PROCEDURE (UNCASED	OR 1BPROCEDURE (UNCASED COIL SHOWN)
1A COIL SHOWN)
		STUB END
DISTRIBUTOR TUBES	TWO PIECE PATCH PLATE	LIQUID LINE	CHECK
	(UNCASED COIL ONLY)
		ORIFICE	EXPANSION
LIQUID LINE ORIFICE HOUSING
	DISTRIBUTOR	HOUSING	VALVE
TEFLON® RING	TUBES		TEFLON®
			RING
FIXED ORIFICE

BRASS NUT

DISTRIBUTOR ASSEMBLY

REMOVE AND DISCARD

WHITE TEFLON® SEAL

(IF PRESENT) LIQUID LINE ASSEMBLY (INCLUDES STRAINER)

AOn fully cased coils, remove the coil access and plumbing panels.

BRemove any shipping clamps holding the liquid line and distributor as- sembly.

CUsing two wrenches, disconnect liquid line from liquid line orifice hous- ing. Take care not to twist or damage distributor tubes during this pro- cess.

TEFLON®

RINGSENSING

LINE

DISTRIBUTOR EQUALIZER

ASSEMBLY LINE

LIQUID LINE

ASSEMBLY WITH

BRASS NUT

MALE EQUALIZER
LINE FITTING	VAPOR
		LIQUID
SENSING BULB	LINE
		LINE

DRemove and discard fixed orifice, valve stem assembly if present and Teflon® washer as illustrated above.

EUse a field−provided fitting to temporary reconnect the liquid line to the indoor unit’s liquid line orifice housing.

AOn fully cased coils, remove the coil access and plumbing panels.

BRemove any shipping clamps holding the liquid line and distributor assembly.

CDisconnect the equalizer line from the check expansion valve equalizer line fitting on the vapor line.

2CONNECT GAUGES AND EQUIPMENT FOR FLUSHING PROCEDURE

DRemove the vapor line sensing bulb.

EDisconnect the liquid line from the check expansion valve at the liquid line assembly.

INVERTED HCFC−22

GAUGE

F Disconnect the check expansion valve from the liquid line orifice

CYLINDER CONTAINS

MANIFOLD

housing. Take care not to twist or damage distributor tubes during this

CLEAN HCFC−22 TO BE

process.

A

USED FOR FLUSHING.

G Remove and discard check expansion valve and the two Teflon® rings.

1

LOW

HIGH

H Use a field−provided fitting to temporary reconnect the liquid line to the

VAPOR LINE

NEW

indoor unit’s liquid line orifice housing.

SERVICE VALVE

OUTDOOR

FLUSHING LINE SET

UNIT

OPENED

CLOSED

The line set and indoor unit coil must be flushed with at least the

EXISTING

3same amount of clean refrigerant that previously charged the

INDOOR

B

system. Check the charge in the flushing cylinder before

UNIT

proceeding.

LIQUID LINE SERVICE

A Set the recovery machine for liquid recovery and start the

VALVE

recovery machine. Open the gauge set valves to allow the

recovery machine to pull a vacuum on the existing system line

TANK

set and indoor unit coil.

RETURN

VAPOR LIQUID

C

B Invert the cylinder of clean HCFC−22 and open its valve to allow

D

INLET

liquid refrigerant to flow into the system through the vapor line

RECOVERY

DISCHARGE

valve. Allow the refrigerant to pass from the cylinder and through

CYLINDER

RECOVERY MACHINE

the line set and the indoor unit coil before it enters the recovery

machine.

A Inverted HCFC−22 cylinder with clean refrigerant to the vapor service

C After all of the liquid refrigerant has been recovered, switch the

recovery machine to vapor recovery so that all of the HCFC−22

valve.

vapor is recovered. Allow the recovery machine to pull down to 0

B HCFC−22 gauge set (low side) to the liquid line valve.

the system.

C HCFC−22 gauge set center port to inlet on the recovery machine with an

D Close the valve on the inverted HCFC−22 drum and the gauge

empty recovery tank to the gauge set.

set valves. Pump the remaining refrigerant out of the recovery

D Connect recovery tank to recovery machines per machine instructions.

machine and turn the machine off.

Figure 11. Removing Metering Device and Flushing

Page 14

506645−01