If traces of oil or glycol are in the system, and the collectors are hot, a
thick fog of vaporized fluid may come out with the air. It is preferable
to open a vent or valve located outdoors to release the air pressure.
To charge the system, connect up a charging system as shown in Figure 5-27. The
charging pump should be a shallow well jet pump, or a jet pump with a shallow well
adapter capable of developing at least 50 PSI in a deadhead (no flow) situation.
(Figure 5-28) A filter or strainer should be between the bucket and the charging
pump inlet. Change the filter after every five systems.
Following Figure 5-27, one hose will run from the bucket or drum to the inlet of the
charging pump, going through a filter or strainer somewhere along the way. Another
runs from the outlet of the charging pump to the fill port of the fill/drain assembly.
This is the downstream port that the check valve arrow points to. The final hose is
connected to the drain port, and leads back to the bucket.
For some systems, especially prepackaged DHW systems, special fittings will be
required for fill/drain assembly connections. (Figure 5-29) For many others, the
fittings end in standard hose threads. Washing machine hoses are useful for
draining and filling.
5.2 REPAIR PROCEDURES