Bosch Greensource CDi Series - Page 34

SM Series Heat Pump
SM Series Heat Pump8733942411 (2017/07) Subject to change without prior notice
34 | Troubleshooting
UNIT TROUBLESHOOTING
Problem Mode Check Possible Cause Action
Cooling Heating
In test mode unit
operates but UPM board
shows fault
X
X
Is Fault LED blinking 3
times?
UPM board is in test
mode
Change the dip switch setting to Normal. This is
part of test mode to ensure that freeze 1 and
freeze 2 sensors are correctly located
Is Fault LED blinking 6
times?
UPM board is in test
mode
Change the dip switch setting to Normal. This is
part of test mode to ensure that freeze 1 and
freeze 2 sensors are correctly located
Unit operates but UPM
board shows fault
X
X
Is Fault LED blinking 3
times?
UPM board is in test
mode
Change the dip switch setting to Normal
Unit operates but no or
short (~10sec) delays on
start or restart
X
X
Is Fault LED blinking 3
times?
UPM board is in test
mode
Change the dip switch setting to Normal
No compressor
operation but fan runs
X
Is fault LED Blinking 1
time?
High Pressure fault - no or
low water flow
Check water valves and/or pumps for proper
operation. Check for water coil blockage.
High Pressure fault - high
water temperature
Check water temperature - is it in range?
High Pressure fault -
fouled or scaled water coil
Check for proper flow rate and water
temperature, but low water side temp rise in
cooling
X
Is fault LED Blinking 1
time?
High Pressure fault - no or
low air flow
Check fan motor for proper operation.
Check air filter
Inspect air coil for dirt/debris
Check duct work - are dampers closed or
blocked?
X
Is fault LED Blinking 2
times?
Low Pressure fault - no or
low air flow
Check fan motor for proper operation.
Check air filter
Inspect air coil for dirt/debris
Check duct work - are dampers closed or
blocked?
Low Pressure fault - low
refrigerant
Check refrigerant pressure with gauge set
X Is fault LED Blinking 2
times?
Low Pressure fault - no or
low water flow
Check water valves and/or pumps for proper
operation. Check for water coil blockage.
Check for proper flow rate and water
temperature, but low water side temp drop in
heating.
Low Pressure fault - low
refrigerant
Check refrigerant pressure with gauge set
X Is fault LED Blinking 3
times?
Freeze fault, water coil -
no or low water flow
Check water valves and/or pumps for proper
operation. Check for water coil blockage.
Freeze fault - low water
temperature
Check water temperature - is it below 40°
entering? If heat pump is connected to a closed
loop with antifreeze check that the “FREEZE 1"
resistor on the UPM board has been cut to set
the unit to antifreeze mode (see UPM features on
pages 12-14).
Freeze fault - low
refrigerant
Check refrigerant pressure with gauge set