Friedrich FPHMR18A3A Service And Parts Manual page 144

R-410A SEALED SYSTEM REPAIR
Pumping Down
– Remove the valve stem caps and confirm that the valve stems
are in the raised position.
– Be sure to use a hexagonal wrench to operate the valve stems.
– Connect the charge hose with the push pin to the service port.
– Open the low-pressure valve on the charge set slightly to air
purge from the charge hose.
when the guage indicates 0 psi.
144
Indoor unit
Lo
CLOSE
Purge the air
Liquid side
Open
2-Way
valve
Gas side
Closed
3-Way
valve
CLOSE
Fig. 505
– Do this quickly so that the gauge ends up indicating 0-15 PSI.
– Tighten the service port nut.
– Be sure to check for gas leakage.
Outdoor unit