Lennox International Inc. 4HP18LT User Manual
Page 6
506470-01
Issue 1007
6. Braze the line set to the service valve. Quench the joints
with water or a wet cloth to prevent heat damage to the
valve core and opening port. The tube end must stay
bottomed in the fitting during final assembly to ensure
proper seating, sealing, and rigidity.
7. Install the thermal expansion valve which is sold
separately and which is approved for use with R410A
refrigerant in the liquid line at the indoor coil (see Refrigerant
Metering Device on page 9).
Page 6
When flushing existing line set and/or indoor coil, be sure to
empty all existing traps. Residual mineral oil can act as an
insulator, preventing proper heat transfer. It can also clog
the thermal expansion valve, reducing system performance
and capacity. Failure to properly flush system as explained
in these instructions will void warranty.
CAUTION
To hang line set from joist or rafter,
use either metal strapping material
or anchored heavy nylon wire ties.
Strapping Material
(around vapor line only)
8
’
8
’
Tape or Wire Tie
Strap the vapor line to the joist or rafter
at 8 intervals then strap the liquid line
to the vapor line.
’
Floor Joist or
Roof Rafter
Metal Sleeve
Floor Joist or Roof Rafter
Tape or Wire Tie
Wire Tie
(around vapor line only)
Figure 6
Refrigerant Line Sets: Installing Horizontal Runs