37SERVICINGIdeal Logic System - Installation and Servicing41 REpLaCEMENT OF COMpONENTsgENERaLWhen replacing aNy component1. Isolate the electricity supply.2. Turn off the gas supply.3. Remove the boiler front panel. Refer to Frame 40.4. Release the retaining clip and swing the control box downinto its servicing position.After replacing ANY component check operation of theboiler, including gas soundness, gas rate and combustiontest.IMpORTaNT.When work is complete, the front panel must be correctlyrefitted - ensuring that a good seal is made.Notes.1. In order to assist fault finding, the control panel hasan LED diagnostic display. The key to boiler faultconditions is shown in Frame 63.2. In order to replace components in Frames 54-61 it isnecessary to drain the boiler. Refer to Frame 53.ThE BOILER MUsT NOT BE OpERaTED WIThOUT ThE FRONT paNEL FITTED42 FaN REpLaCEMENT1. Refer to Frame 41.2. Disconnect the electrical leads from the fan.3. Undo the gas pipe union connection to theinjector housing.4. Remove the extended nut retaining the fanmounting bracket.5. Lift and remove the fan and venturi assembly.6. Remove the screw and twist venturi anti-clockwise to remove venturi assembly, notingthe orientation of the venturi in relation to thefan body.7. Transfer the venturi assembly to the new fan,replacing the ‘o’ ring if evidence of damage ordeterioration is visible.8. Fit the new fan / venturi assembly ensuring theretaining tabs are correctly positioned and thefan outlet sealing gasket is correctly positionedand free from damage. Refit the extended nut.9. Reassemble the boiler in reverse order, takingcare not to overtighten the screw on the fanmounting bracket.10. Check the operation of the boiler. Refer toFrames 30 & 31.246348 Retaining TabssERVICINg