Hayward HeatPro HP50TA Troubleshooting Manual page 28

PS/FLo
Correct
connections.
Replace display
board and wire
harness
Note: Always check operation of pressure switch by
turning off pool pump after adjusting pressure switch.
Heat pump should cut off when pool pump is not running.
Flow Chart
Water flow issue. Heater requires a minimum flow
of 30 GPM. The water pressure switch is not
sensing pressure. Is filter pump on and filter
NO
Turn on filter
pump or clean
filter.
Close Bypass
Check all
connections
NO
at display board and
wire harness.
Connections OK?
YES
Unit operates
PS/FLo
clean? Bypass closed?
YES
Check continuity
(ohms reading)
of pressure switch. Ohms reading zero?
Unit off & filter pump running.
YES
With meter attached to terminals on
pressure switch, adjust dial on switch
counter clockwise until switch closes-
reading of zero Ohms.
Switch closed (zero Ohms)?
YES
Replace pressure
NO
NO
switch.