Sanyo CM1972 - Manual (Page 61)

9-7. Charging Additional Refrigerant
9-7-1. When Tubes are Extended
Observe the proper amount of refrigerant as stated in this service manual or the installation manual that came
with the indoor unit. Charge additional refrigerant in liquid state only.
9-8. Retro-Fitting Existing Systems
9-8-1. Use of Existing Units
Never use new refrigerant R410A for existing units which use R22. This will cause the air conditioner to
operate improperly and may result in a hazardous condition.
9-8-2. Use of Existing Tubing
If replacing an older unit that used refrigerant R22 with a R410A unit, do not use its existing tubing. Instead,
completely new tubing must be used.
CAUTION
Never charge additional refrigerant if refrigerant is leaking from the unit. Follow
instructions given in "9-6. In Case Refrigerant is Leaking" and completely carry out
repairs. Only then should you recharge the refrigerant.
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