Originally Posted by castingabout
It appears my Duo-Therm AC/heat pump mod 630515 has lost its refrigerant charge. Is it possible to recharge the system? If not is the only option to replace the unit?
THX in advance for your help.
Re-charging is NOT possible in it's present form, as the unit was hermetically sealed at the factory after the refrigerant charge was applied. If you can find that special
HVAC tech who will take on the job, it can be done, but generally only after you remove the unit from the roof.
Thee are special Schrader valve fittings that can be soldered into the ends
of the existing tubing (hi and low sides) that were crimped and solder filled and when properly done, will hold the charge. The problem is finding the reason that you lost the initial charge. Locating a leak and repairing that is generally time consuming and costly.
I had it done to a unit where the owner had pierced one of the tubes at the end of the evaporator. It was in an accessible location, and the HVAC tech repaired the hole, added the Schrader fittings as described above, re-charged the unit and it is still working today.