FLUSHING AND FILLING THE SYSTEM USING 3 WAY
VALVES
Step 1
Use water and a high volume head circulator pump to flush
air and debris and to fill the loop system.
- Refer to recommendations provided by IGSHPA when
choosing a pump for the flushing process.
- It is recommended that pump suction be from the bottom
of a large volume container. Use a suction line strainer to
prevent debris discharged into the container from being
recycled to the system.
Step 2
Pump water into the system by connecting the pump
discharge hose to one (not both) of the 1” NPT water
connections located on the sides of the module.
Connect a return hose to the opposite side of the module to
discharge debris and air as water is added to the loop.
Step 3
Rotate the module valves as shown in step 3 diagram:
Step 4
Start the pump. Add anti-freeze and water to the container
as needed so that no air enters the system. This will push
any air out of the loop. If flushing assembly is equipped with
valves to reverse flow direction, do so occasionally to help
remove trapped air. When bubbles cease in the return hose
container, the earth loop has been completely flushed.
Step 5
Flush the heat pump. To do so, simply rotate the valves as
shown in step 5 diagram while the pump is running. Flush
the heat pump using the same procedure as used to flush
the earth loop.
Pressurizing The System
Step 6
After flushing and filling the system, rotate the module valve
discharging into the flush container as shown in step 6A
diagram to pressurize the loop. Then turn the valves as in
step 6B.
Step 7
Turn off the flush cart pump. The system should remain
pressurized. Release excess pressure by rotating either
module valve to allow a small amount of water to pass
through and out of the system and into the container. Some
initial loss of pressure can be expected and is due to the
expansion of the earth loop pipe under pressure. The
pressure will stabilize if the system has no leaks.
Step 8
Flushing, filling and pressurization should be complete.
Start the loop pump module circulators.
Page 10
To Earth Loop From Earth Loop
From
Flush
Cart
To
Flush
Cart
Step 3
From Heat PumpTo Heat Pump
Step 5 To
Flush
Cart
From
Flush
Cart
Step 9
Troubleshoot. If for some reason the circulators are not
operating, power off and diagnose the problem.
Step 10
Using a single water pressure gauge, measure the pressure
drop at the pressure/temperature plugs across the heat
pump heat exchanger. Compare the measurement with the
flow versus the pressure drop table (Table#3) and determine
the actual flow rate. If the flow rate is low, recheck the
selection of the loop pump module model for sufficient
capacity. If the model is correct, there is likely trapped air or
a restriction in the flow circuit.
System pressure should increase rapidly as the flush pump
works to force more water into the system. Additional
flushing of the loop is needed if the water level in the loop
falls. This shows that there is air in the system.
System operating pressures should be between 10 to 40
PSI.
From Heat Pump To Heat Pump
To Earth Loop From Earth Loop
Step 6B
From Heat PumpTo Heat Pump
Step 6A
From
Flush
Cart
Pressurize Loop
