Ideal Boilers mini HE C24 Installation And Servicing

SERVICINGmini HE --- Installation & Servicing 3750 EXPANSION VESSEL REPLACEMENTIf the CH expansion vessel is faulty, there are 2 options:A If it has a punctured diaphragm, but is otherwise leak free,than it can be left in place and a new vessel added to thereturn side of the system, external to the boiler, provided itis of adequate capacity and pre---charge pressure.B If there is at least 400 mm (16”) clearance above theboiler, the expansion vessel can be changed withoutremoving the boiler (rear exit flues will have to bedisturbed).For option B, proceed as follows:1 Disconnect the electrical supply.2 Gain access to the controls area by removing the boilerfront panel (refer to frame 34).3 Close off the isolating cocks of the CH circuit at thebottom of the boiler.4 Release system pressure by opening the main circuitdrainage cock.Do not release CH pressure using the pressure reliefvalve. It may cause debris within the system to foulthe valve.5 Completely unscrew the connection A, the locknut B andremove the expansion vessel from the top of the boiler.AB6 Re---assemble in reverse order.51 FAN REPLACEMENT1 Disconnect the electrical supply.2 Remove outer and inner casing.3 Disconnect the connectors A and the earth connection B.4 Disconnect the pipe which connects the venturi device tothe air pressure switch.5 Unscrew the screw C and remove the fan holder bracketD.A BCD6 Remove the fan by sliding it towards left (see the arrow).7 Re---assemble in reverse order.Note: Always take care when handling the fan, in order topreserve the balance of the impeller.To correctly connect the venturi device to the air pressureswitch, refer to the following illustration.--- +52 VENTURI REPLACEMENT1 Remove the fan (see frame 51).2 Remove and replace the venturi device A by unscrewingthe screw B.3 Re---assemble in reverse order.ABSERVICING