Troubleshooting; Unit Troubleshooting - Bosch QV Series Installation, Operation And Maintenance Manual

36 | Troubleshooting

TROUBLESHOOTING

Unit Troubleshooting

NOTICE: If troubleshooting a system that is
low on refrigerant due to a system leak, do
not simply add refrigerant. The leak must be
found and repaired per F-Gas regulation.
Problem
Cooling
X
NO
COMPRESSOR
OPERATION
BUT FAN RUNS
X
8733829041 (2021/07)
Unit Troubleshooting
Mode Check
Heating
Is the Fault
LED
blinking one
(1) time?
Is the Fault
LED
X blinking one
(1) time?
Is the Fault
LED
blinking two
(2) times?
Subject to change without prior notice
Possible
Cause
High Check water valves and/or pumps for
pressure proper operation. Check for water coil
fault—no or blockage.
low water
flow
High Check water temperature—is it in
pressure range?
fault—high
water
temperature
High Check for proper flow rate and water
pressure temperature, but low-water-side temp
fault—fouled rise in cooling.
or scaled
water coil
Check the fan motor for proper
operation.
High
pressure
Check the air filter.
fault—No or
Inspect the air coil for dirt/debris.
low air flow
Check duct work—Are dampers closed
or blocked?
Check the fan motor for proper
operation.
Check the air filter.
Low pressure
fault—No or
low air flow
Inspect the air coil for dirt/debris.
Check duct work—Are dampers closed
or blocked?
Low pressure Check refrigerant pressure with a
fault—Low gauge set.
refrigerant
QV Series Heat Pumps
Action
QV Series Heat Pumps