3.19 Yearly appliance maintenance and check.
e following checks and maintenance should be performed
at least once a year.
- Clean the fume side of the heat exchanger.
- Clean the main burner.
- Check correct lighting and operation.
- Check correct settings of the burner in domestic hot water
and heating phases.
- Check correct operation of control and adjustment devices
and in particular:
- activation of main electrical switch on boiler;
- system control thermostat intervention;
- domestic hot water control thermostat activation.
- Check tightness of gas circuit section between the appli-
ance on/off valve (cock) and gas valve (cut out). Inserting
a differential digital pressure gauge (with scale in tenths of
mm or Pascal) in the pressure point ahead of the gas valve
and subsequently closing the boiler on/off valve (cock)
and closing the gas valve, after 5 minutes there must be
no pressure variation on the gauge.
- Check activation of the device against no gas ionization
flame control:
- ensure intervention time is less than ten seconds.
- Visually check for water leaks or oxidation from/on con-
nections and traces of condensate residuals inside the sealed
chamber.
- By means of the condensate drain plug check for any
residuals of material possibly blocking the flow of con-
densate.
- Check contents of the condensate drain trap.
- Visually check that the water safety valve drain is not
blocked.
- Check that, after discharging system pressure and bringing
it to zero (read on boiler pressure gauge), the expansion
tank charge is at 1.0 bar.
- Check that the system static pressure (with system cold
and after refilling the system by means of the filler cock)
is between 1 and 1.2 bar.
- Visually check that the safety and control devices have not
been tampered with and/or shorted, and in particular:
- temperature safety thermostat;
- Check the condition and integrity of the electrical system
and in particular:
- electrical feed wires must be inside the whipping;
- there must be no traces of blackening or burning.
30
INST
ALLER
USER
TECHNICIAN
31
INST
ALLER
USER
TECHNICIAN
