Air Source Heat Pump Water Heater
18
Figure 7-3 Opening the fluid valve and air valve
Figure 7-4 Vacuum pump connection diagram
(2) Vacuum pump
1) Connect the filling hose to the fluoride injection mouth of the air valve.
Ensure that the valve cores of the air valve and fluid valve are tightly
closed.
2) Connect the joint of the filling hose to the vacuum pump, as shown in
Figure 7-4.
3) Fully open the low pressure valve of the pressure gauge.
4) Start the vacuum pump to vacuumize the air for 20 minutes or more,
and ensure that the pressure gauge pointer points to -1.0 x 10
5
Pa
(-76cmHg). Close the low pressure valve, and stop the vacuum