Bosch Greensource CDi Series Installation, Operation And Maintenance Manual page 34

34 | Troubleshooting
Problem Mode
Cooling
In test mode unit
X
operates but UPM board
shows fault
Unit operates but UPM
X
board shows fault
Unit operates but no or
X
short (~10sec) delays on
start or restart
X
X
No compressor
operation but fan runs
8733942411 (2017/07)
UNIT TROUBLESHOOTING
Check
Heating
Is Fault LED blinking 3
times?
X
Is Fault LED blinking 6
times?
Is Fault LED blinking 3
X times?
Is Fault LED blinking 3
X times?
Is fault LED Blinking 1
time?
Is fault LED Blinking 1
X time?
Is fault LED Blinking 2
times?
X Is fault LED Blinking 2
times?
X Is fault LED Blinking 3
times?
Subject to change without prior notice
Possible Cause
UPM board is in test
Change the dip switch setting to Normal. This is
mode
part of test mode to ensure that freeze 1 and
freeze 2 sensors are correctly located
UPM board is in test
Change the dip switch setting to Normal. This is
mode
part of test mode to ensure that freeze 1 and
freeze 2 sensors are correctly located
UPM board is in test Change the dip switch setting to Normal
mode
UPM board is in test Change the dip switch setting to Normal
mode
High Pressure fault - no or Check water valves and/or pumps for proper
low water flow operation. Check for water coil blockage.
High Pressure fault - high Check water temperature - is it in range?
water temperature
High Pressure fault -
fouled or scaled water coil temperature, but low water side temp rise in
Check fan motor for proper operation.
High Pressure fault - no or
low air flow
Check duct work - are dampers closed or
Check fan motor for proper operation.
Low Pressure fault - no or
low air flow
Check duct work - are dampers closed or
Low Pressure fault - low Check refrigerant pressure with gauge set
refrigerant
Check water valves and/or pumps for proper
Low Pressure fault - no or operation. Check for water coil blockage.
low water flow
temperature, but low water side temp drop in
Low Pressure fault - low Check refrigerant pressure with gauge set
refrigerant
Freeze fault, water coil - Check water valves and/or pumps for proper
no or low water flow operation. Check for water coil blockage.
Check water temperature - is it below 40°
entering? If heat pump is connected to a closed
loop with antifreeze check that the "FREEZE 1"
Freeze fault - low water resistor on the UPM board has been cut to set
temperature the unit to antifreeze mode (see UPM features on
Freeze fault - low Check refrigerant pressure with gauge set
refrigerant
SM Series Heat Pump
Action
Check for proper flow rate and water
cooling
Check air filter
Inspect air coil for dirt/debris
blocked?
Check air filter
Inspect air coil for dirt/debris
blocked?
Check for proper flow rate and water
heating.
pages 12-14).
SM Series Heat Pump