26. CONNECTING THE EXTERNAL PROBE
The wiring harness leaving the control board includes to RED wires fitted with faston covers. Connect the external probe
to these two wires.
With the external probe connected it is possible to change the curve "kt" (Graph 1) by means of the
"kt" curves
To optimise boiler efficiency, carry out the following annual controls:
• check the appearance and air-tightness of the gaskets of the gas and combustion circuits;
• check the state and correct position of the ignition and flame-sensing electrodes;
• check the state of the burner and make sure it is firmly fixed;
• check for any impurities inside the combustion chamber.
Use a vacuum cleaner to do this;
• check the gas valve is correctly calibrated;
• check the pressure of the heating system;
• check the pressure of the expansion vessel;
• check the fan works correctly;
• make sure the flue and air ducts are unobstructed;
WARNINGS
Before commencing any maintenance operations, make sure the boiler is disconnected from the power supply.
Afterwards, move the knobs and/or operating parameters of the boiler to their original positions.
INSTRUCTIONS FOR FITTERS
TM
TM = Delivery temperature range
Te = External temperature
27. ANNUAL SERVICING
20
+/-
buttons.
Te
Chart 2
926.527.2 - EN