Pentair ThermalFlo, User Manual, Page: 18 / 40

10
ThermalFlo Installation and User’s Guide
Multiple Heat Pump Connections
All plumbing on multiple heat pump installations must be done in parallel see Figures 9 and 10. An equal flow
of water to each heat pump is important for optimum operation.
NOTE: It may be necessary to adjust water pressure switch if a unit is installed below the water
level. See page 20 for details on when and how to adjust the pressure switch.
Each heat pump allows a maximum flow rate of 125 gpm and requires a minimum of 30 gpm.
24 inches min. clearance around evap.
Extend12" past
end heater inlet
for hydraulic
balancing
Extend12" past
end heater inlet
for hydraulic
balancing
Pool Pump
Flow Meter
Minimum
2" PVC Pipe
2" PVC Pipe
Flow Meter
To Pool
OPTIONAL
2" Check Valve Bypass
Check Valves are
optional on heater inlets
but will help system
balancing
24"
Figure 9. Two Heat Pump Plumbing Layout
24 inches min. clearance around evap.
Extend12" past
end heater inlet
for hydraulic
balancing
Extend12" past
end heater inlet
for hydraulic
balancing
Pool Pump
Flow Meter
Minimum
3" PVC Pipe
2" PVC Pipe
Flow Meter
To Pool
3" Ball Valve Bypass
Check Valves are
optional on heater inlets
but will help for system
balancing
24"
2" PVC
Pipe
2" PVC
Pipe
2" PVC
Pipe
3" PVC Pipe 3" PVC Pipe
Figure 10. Four Heat Pump Plumbing Layout