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Troubleshooting and Diagnostics
L. Too high discharge pressure
M. The water chiller cannot function in heating (CGAR).
N. Excessively low pressure—heating condition
K. Too low discharge pressure
Possible cause
Solution
Insufficient of excessive cooling air, flow choking
Clean the coiler and check whether fan and motor are normal.
Air or non-condensed gas present in the system
(abnormally hot condenser)
Vacuumize the system and re-fill it with coolant.
Excessive coolant (high supercooling degree, low
superheat degree, and high suction pressure)
Reclaim redundant coolant.
Too high system load
Lower the load.
Poor pressure control over condensation fan or fan (a
certain fan fails, and too high pressure of condenser)
Repair or change the switch.
Possible cause
Solution
Wrong or poor control line
Check the control line.
Four-way valve failure
Change the four-way valve.
Possible cause
Solution
Insufficient coolant
Replenish coolant.
Too low or too cold of air entering the coiler
Clean the coiler and check whether fan and motor are normal.
The water chiller is operated at a temperature below
minimum operating environmental temperature.
Provide an environmental temperature disconnecting switch.
Expansion valve failure
Change the expansion valve.
Possible cause
Solution
Too high cooling load (high supply water temperature)
Check whether the filter screen is blocked and whether the
balance valve is correctly set.
Too low water flow
Check whether the filter screen is blocked and whether the
balance valve is correctly set.
