Lennox FCM 85 Installation, Operating And Maintenance page 98

MAINTENANCE PLAN
Check HP / LP safety switches
Check outdoor fans and fan guards
Check position of all sensors
Check and clean if necessary all fresh
air grilles
Clean condensate drain, indoor and
outdoor coils (following local
regulations)
Check electric heater element for
excessive corrosion
Check anti-vibration mountings, for
wear and tear.
Check refrigeration circuit for traces of
acid in the oil
Check Glycol concentration in the HWC
circuit
Check defrost cycle with 4-way valve
inversion.
Gas burner module check for corrosion
Sweeping and cleaning the gas burner
Gas supply pressures / connections
checks
Gas regulation valve settings
Check gas burner safety switches
FLEXYII-IOM-0409-E
Install manifold gauges on the circuit to be checked. Shut
down the axial fans and wait for the HP switch to shut
down the compressor: 29bar (+1 / -0) auto-reset 22bar
- 0.7) Reconnect fans. Switch off the centrifugal supply fan
and wait for the LP switch to cut out: 0.5bar (+ - 0.5) reset
1.5bar (+-0.5).
Check the fan blades conditions and all fan guards and
protections
Check the good positioning and operation of all sensors of
all sensors. Check the values given in the control system.
Replace sensor if necessary
Check the fresh air grilles (if fitted). If dirty or damaged,
remove them from unit and clean with high pressure water
cleaner. Refit on unit once clean and dry.
Visually check the coils for dirt. If not too dirty, cleaning
with a light brush may be enough (WARNING: Fins and
copper tubes are very fragile! Any damage WILL reduce
the performances of the unit). If very dirty, deep industrial
cleaning is required using de-greasing agents.(External
contractors must be called).
Isolate the unit; Pull the electric heater out of the heater
module box and check the resistances of traces of
corrosion; Replace resistance as required;
Visually check anti-vibration mountings on compressors
and centrifugal fan. Replace if damaged.
Take a sample of oil from the refrigeration circuit.
Check the glycol concentration in the pressurised water
circuit. ( a concentration of 30% gives a protection down to
aprox. -15°C) check the circuit pressure
Switch the unit to heat pump mode. Change the set point
to obtain the standard defrost mode and reduce the cycle
time to the min value. Check the operation of the defrost
cycle.
Pull out the burner to access the tubes (refer to Gas burner
section in the IOM)
Clean the in-shot burners and the blower wheel lightly with
a brush. Sweep the flue and flue box. Wipe-off the dust
from the housing of the motor. Clean combustion air inlet
louvers Pull-out baffles from the tubes, sweep the tubes
CHECK FLUE BOX GASKET
refer to Gas burner section in the IOM for details
refer to Gas burner section in the IOM for details
refer to Gas burner section in the IOM for details
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15
5
5
5
1h if
cleaning
1h if
replacement
1h if
replacement
30
30
30
30
15
30
30
Page 97