Removing Indoor Unit Metering Device - Lennox Merit Series 13ACX Installation Instructions Manual

NOTE − The fixed orifice or TXV metering device at the
indoor unit will allow low pressure nitrogen to flow through
the system.)
NOTE − Use silver alloy brazing rods with five or six percent
minimum silver alloy for copper−to−copper brazing or 45
percent silver alloy for copper−to−brass or copper−to−steel
brazing.
6. Braze the liquid line to the liquid line service valve.
Turn off nitrogen flow.
IMPORTANT
Repeat procedure starting at paragraph 4 for brazing the
suction line to service port valve.
7. After all connections have been brazed, disconnect
manifold gauge set the from service ports and remove
wrapping. Reinstall the service port core for both of the
outdoor unit's service valves.

Removing Indoor Unit Metering Device

Remove the existing HCFC−22 fixed orifice or TXV from
the indoor coil. The existing indoor unit HCFC−22 metering
device is not approved for use with HFC−410A refrigerant
and may prevent proper flushing.
REPLACEMENT PARTS
If replacement parts are necessary for the indoor unit,
order catalog number 69J46 (LB−95325A). The kit includes
the following:
LIQUID LINE ORIFICE HOUSINGS (10)
TEFLON RINGS (20)
BRASS NUTS (10)
LIQUID LINE ASSEMBLIES
(INCLUDES STRAINER) (10)
Figure 15. Kit 69J46 Components
PISTON
RETAINER
STRAINER
COPPER
TUBE
LIQUID LINE
ASSEMBLY
Page 9
TYPICAL FIXED ORIFICE REMOVAL PROCEDURE
DISTRIBUTOR TUBES
LIQUID LINE ORIFICE HOUSING
TEFLON RING
VALVE STEM
VALVE STEM CAP
Figure 16. Typical Fixed Orifice Removal
1. On fully cased coils, remove the coil access and
plumbing panels.
2. Remove any shipping clamps holding the liquid line
and distributor assembly.
3. Using two wrenches, disconnect liquid line from liquid
line orifice housing. Take care not to twist or damage
distributor tubes during this process.
4. Remove and discard fixed orifice, valve stem
assembly if present and Teflon ring as illustrated in
figure 16.
5. Use a field−provided fitting to temporary reconnect the
liquid line to the indoor unit's liquid line orifice housing.
TYPICAL TXV REMOVAL PROCEDURE
1. On fully cased coils, remove the coil access and
plumbing panels.
2. Remove any shipping clamps holding the liquid line
and distributor assembly.
3. Disconnect the equalizer line from the TXV equalizer
line fitting on the suction line.
4. Remove the suction line sensing bulb as illustrated in
figure 17.
5. Disconnect the liquid line from the TXV at the liquid line
assembly.
6. Disconnect the TXV from the liquid line orifice housing.
Take care not to twist or damage distributor tubes
during this process.
7. Remove and discard the TXV along with the two Teflon
rings.
REMOVE AND DISCARD
VALVE STEM ASSEMBLY
FIXED
(IF PRESENT)
ORIFICE
BRASS NUT
LIQUID LINE ASSEMBLY
(INCLUDES STRAINER)
(Uncased Coil Shown)
13ACX SERIES