Aquacal Heat Pump

Troubleshooting Using Displayed Codes

Interpreting Error Codes

The HP7R heat pump microprocessor controller is designed to be self-diagnostic through the display

of various fault codes.

Owners & Operators: If you believe you are experiencing a problem with the heater , and feel a need to

call the factory for assistance, it will be beneficial to let the factory Service Representative know if any

code is being displayed. Having this information at hand will permit the Service Representative to work

through–with you–any site related issues causing or contributing to the problem. Then, if after working

through site-related issues the heater is still not functioning correctly, the Service Representative will

offer to set up a service visit. As necessary, please Contact AquaCal Customer Support Group (727-

823-5642).

Dealers and Service Centers: For troubleshooting use, listed below are all possible fault messages

output by the microprocessor, what the codes mean, and possible causes with solutions for the

indicated problem. Please contact AquaCal Technical Support Group, as necessary (727-823-5642).

Controls Configuration & Adjustments...

WARNING ! Failure to heed the following may result in permanent

injury or death.

Heat pumps contain no owner or operator repairable components. Repairs must not be

attempted by untrained and/or unqualified individuals. If service is deemed necessary , contact

installing dealer or AquaCal Customer Support at (727) 823-5642

Message Error Description Possible Cause

[dPO] Defrost S ensor Open Cut or loose def rost sensor wiring.

[PO]

[dPC]

Water Tem perature Sensor Open

Defrost Sensor Shorted

Cut or loose temperature sensor wiring.

Short circuit in defrost s ensor wiriting or defec tive defrost sensor.

[PC]

[LP]

Water Tem perature Sensor Short ed

Refrigerant S ys tem Low

Pressure Switch Open

Short circuit in water t emperature s ensor or defecti ve sensor.

System refrigerant charge low, defecti ve l ow press ure switch, cl ogged

evaporator coil , or defecti ve wiring.

[HP]

[HP5]

Refrigerant S ystem Hi gh Pressure

Switch Open

5 High Press ure Faul ts Withi n One (1)

Call for Heat i ng or Cool i ng (Lock Out

Condition)

Low water fl ow, def ective high pres sure switch, or defective wiring.

See causes for [HP]

[LP5] 5 Low Pressure Faults Within One (1)

Call for Heat i ng or

Cooling (Lock Out Condition)

See causes for [LP]

[OTA]

[FLO]

Over Temperature Alarm <

Temperature over 110 F (Uni t

Locked)

Low or No Wat er Fl ow

Detected

Defect i ve c ompress or contact or, defecti ve controller, or defective water

tem perat ure sensor.

Circulating pump off, water filter dirty, isolation valves set impropery,

or defect i ve pressure switc h.

[FS] Heater in Defrost Mode

(Heat-Only Unit s) Normal function in l ower air temperatures. Fan continues to run and compresso

is off. Compressor will restart when air-coil temperature reaches 38 F or above.

[CSE]

[CEr]

Control Sys tem Error

Communicati on Fault

Controller may need to be reset . Disconnect then rec onnect power to control l er.

If error c ont inues, replac e control board, di splay board, or both.

Loss of communicat i on bet ween main board and display board. Reset cont rol l e

or replace comm uni cation cable.