Bosch Greensource CDi TW Series Installation, Operation And Maintenance Manual page 32

32 | Troubleshooting
Problem
INSUFFICIENT
COOLING OR
HEATING
Table 9 Unit Troubleshooting
HRP Troubleshooting
Problem
NO FLOW
LOW FLOW
HIGH-WATER
TEMPERATURE
LOW HEAT
OUTPUT
Table 10 HRP Troubleshooting
8733954853 (2020/04)
Unit Troubleshooting
Possible Cause
Unit Undersized
Fluid Flow
Refrigerant Charge
Compressor
Reversing Valve
Operating Pressures
TXV
Moisture, Non-
condensables
Possible Cause
No Power
On/Off Switch Position
Compressor Contactor
Broken or loose wires
Air Lock
Stuck Pump Shaft/Impeller
Defective Pump
Kinked or Undersized Water Piping
Water Temp Limit Closed
Scaled or Fouled Heat Exchanger
Subject to change without prior notice
Greensource CDi Series TW Model
Checks and Corrections
Recalculate heating and or cooling loads. If excessive,
possibly adding insulation and shading will rectify the
problem.
Check for the lack of adequate fluid flow.
Refrigerant charge low causing inefficient operation.
Check for defective compressor. If discharge is too low
and suction pressure is too high, compressor is not
pumping properly. Replace compressor.
Defective reversing valve creating bypass of refrigerant
from discharge of suction side of compressor. Replace
reversing valve.
Compare unit operation pressures to the pressure/
temperature chart for the unit.
Check TXV for possible restriction or defect. Replace if
necessary.
The refrigerant system may be contaminated with
moisture or non-condensables. Reclaim refrigerant,
replace filter dryer, evacuate the refrigerant system, and
recharge with factory recommended charge.
Checks and Corrections
Check the power supply.
Set switch to "ON" position.
Engage the heat pump contactor.
Repair or tighten the wires.
Purge the air from piping system.
Remove the pump cartridge and clean.
Replace the pump.
Repair the kink and check for proper line
size.
Check for a stuck limit switch.
Check for a sensor not securely attached to
the line.
Clean the heat exchanger.
Greensource CDi Series TW Model