Bosch FHP EC Large Series Installation, Operation And Maintenance Manual page 27

EC Series
Problem
NO FLOW
LOW FLOW
HIGH WATER
TEMPERATURE
LOW HEAT OUTPUT
EC Series
HRP Troubleshooting
Possible Cause
No Power
On/Off Switch Position
Compressor Contactor
Broken or loose wires
Air Lock
Stuck pump shaft/impeller
Defective pump
Kinked or under sized water piping
Water temp limit closed
Scaled or fouled heat exchanger
Checks and Corrections
Check power supply
Set switch to "ON" position
Engage heat pump contactor
Repair or tighten wires
Purge air from piping system
Remove pump cartridge and clean
Replace pump
Repair kink and check for proper line size
Stuck limit switch
Sensor not attached securely to line
Clean heat exchanger
.
Troubleshooting | 27
T111970289 (2015/01)