OPERATION AND MAINTENANCE MANUAL
Wall Mounted 0121…0661
Monobloc Wall Mounted Unit - WMA/WMF 0121-0181-0251-0281-0331-0551-0661 - Rev. 2.0. - Date: 18-07-2000 EN
23 (32)
CHANGING THE ELECTRIC HEATING ELEMENTS
(models WM* 0551-0661)
The heater elements are in front of the MVE radial fan: for access,
remove the top front panel of the unit and the safety cover.
IMPORTANT: before working on the electric heating element, switch
off the power supply by moving the main switch to the OFF position
(O) and wait for the element to cool.
CLEANING AND CHANGING THE CONDENSATE DRAIN TUBE
If necessary, change the condensate drain tube starting from the drain tray under the evaporator coil. To clean the
tube, disconnect it from the tray and use a use a jet of water.
ADJUSTING THE REFRIGERANT CHARGE
The unit’s refrigerant circuit is supplied already charged with R22 or R407C.
Check the type of refrigerant to use on the data plate of the unit and of the compressor
.
If necessary, top up the charge using only the refrigerant and oil specified in the unit manual. Drain the refrigerant
circuit completely, making sure that no refrigerant gas leaks into the environment, then create a vacuum in the
circuit. A pressure of less than 100 Pa absolute (0,7 mm Hg) must be maintained in order to evacuate all air and
moisture traces.
Start the compressor and slowly charge the refrigerant circuit via the special valve until the pressure in the line
stabilises and the bubbles in the sight glass disappear. This valve is on the vertical section of piping immediately
downstream of the thermostatic valve
Filter Drier
Sight
glass
Thermostatic valve
