Troubleshooting - Bosch LV009 Installation And Maintenance Manual

LV Heat Pump Series

TROUBLESHOOTING

Problem
No compressor operation
but fan runs
LV Heat Pump Series
UNIT TROUBLESHOOTING
Mode Check
Cooling Heating
X
Is fault LED Blinking 1
X
X
Is fault LED Blinking 2
times?
X
Is fault LED Blinking 3
X
times?
Possible Cause
High Pressure fault - no or
low water flow
High Pressure fault - high
water temperature
High Pressure fault -
fouled or scaled water coil
time?
High Pressure fault - no or
low air flow
Low Pressure fault - no or
low air flow
Low Pressure fault - low
refrigerant
Low Pressure fault - no or
low water flow
75Unit
Low Pressure fault - low
refrigerant
Freeze fault, water coil -
no or low water flow
Freeze fault - low water
temperature
Freeze fault - low
refrigerant
Troubleshooting | 35
Action
Check water valves and/or pumps for
proper operation. Check for water
coil blockage.
Check water temperature - is it in
range?
Check for proper flow rate and water
temperature, but low water side
temp rise in cooling
Check fan motor for proper
operation.
Check air filter
Inspect air coil for dirt/debris
Check duct work - are dampers
closed or blocked?
Check fan motor for proper
operation.
Check air filter
Inspect air coil for dirt/debris
Check duct work - are dampers
closed or blocked?
Check refrigerant pressure with
gauge set
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.
Check refrigerant pressure with
gauge set
Check water valves and/or pumps for
proper 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"
resistor on the UPM board has been
cut to set the unit to antifreeze mode
(see UPM features on pages 15-17).
Check refrigerant pressure with
gauge set
8 733 905 683 (2016/09)