Page 71
Symptom Cooling Heating
Who can take
corrective action U
= User
S = specialised
personnel
Probable cause Possible remedy
E The compressor
does not start
because the
minimum
pressure switch
has tripped
Pressure switch out of order Check and replace.
x x s
Unit completely void of refrigerant See point G.
x u
Water circulation pump blocked
Unlock the pump
x s
Water circulation pump blocked and
defective
Check the pump and replace if necessary
x s
Presence of frost on the evaporator
coil
See point N.
x x s
Refrigerant filter clogged Check and replace.
x x s
Expansion device that is not working
properly
Check and replace if necessary.
Presence of moisture in the
refrigerant circuit
Replace the filter, dry and recharge
G Lack of gas
x x s
Loss in the refrigerant circuit
Check the cooling circuit using a leak
detector after pressurising the circuit to
approximately 4 bars.
Repair, evacuate and refill.
H Frost in the
liquid line
downstream from
a filter
x x s
The filter is clogged Replace the filter
I The unit works
continuously
without ever
stopping
Lack of refrigerant gas See item G.
x x u
Incorrect tuning of the operating
thermostat
Check and set.
Excessive thermal load Reduce the thermal load
x x s
Compressor does not give the
thermal output
Check, change or revise
x x s
The liquid filter is clogged Replace.
L The unit works
regularly but with
an insufficient
capacity
x x s
Low refrigerant charge
See point G.
x x s
4-way reversing valve defective
Check the power supply and the coil of the
valve and replace the valve