39Installation and ServicingSECTION 3 - SERVICING3.1 SERVICING SCHEDULEFor the very latest copy of literature for specification & maintenance practices, visit www.zanussi-boilers.co.uk where you will beable to download the relevant information.WARNING. Always turn OFF the gas supply at the gas service cock, and switch OFF and disconnect the electricitysupply to the appliance before servicing.Combustion testing must be carried out by a competent person using a combustion analyser conforming to BS7927.To ensure the continued safe and efficient operation of the appliance it is recommended that it is checked at regular intervals andserviced as necessary. The frequency of servicing will depend upon the installation condition and usage but should be carried outat least annually.It is the law that any service work must be carried out by a Gas Safe Registered Engineer. In IE service work must be carried outby a Registered Gas Installer (RGII).Flue Sampling PointAir SamplePointEnsure all caps and sealsare re-fitted after useGENERALPlease Note: During Servicing, and after anymaintenance or change of part of the combustioncircuit, the following must be checked:- The integrity of the flue system and the flue seals.- The integrity of the boiler combustion circuit andthe relevant seals.- The operational (working) gas inlet pressure atmaximum rate.- The gas rate.- The combustion performance.COMPETENCE TO CARRY OUT THE CHECKOF COMBUSTION PERFORMANCEPlease Note: BS 6798:2009 Specification forinstallation and maintenance of gas-fired boilers ofrated input not exceeding 70kW net advises that:- The person carrying out a combustionmeasurement should have been assessed ascompetent in the use of a flue gas analyser and theinterpretation of the results.- The flue gas analyser used should be one meetingthe requirements of BS7927 or BS-EN50379-3and be calibrated in accordance with the analysermanufacturer’s requirements, and- Competence can be demonstrated by satisfactorycompletion of the CPA1 ACS assessment, whichcovers the use of electronic portable combustiongas analysers in accordance with BS7967, Parts 1to 4.Note. In order to carry out either servicing or replacement of componentsthe boiler front panel must be removed. Refer to Section 3.2.PRELIMINARY INSPECTION1. Light the boiler and carry out a pre-service check, noting anyoperational faults (refer to appropriate fault finding chart asnecessary).2. Check the flue terminal (and terminal guard if fitted) is undamagedand clear of any obstruction.3. Check combustion by connecting the flue gas analyser to the fluegas sampling point as shown in the diagram and measure CO andCO 2 at maximum rate. Repeat at minimum rate.If the CO / CO2 ratio is greater the 0.004 please proceed to “CheckProcedure”.CHECK PROCEDURE1. Check all water and gas joints for signs of leakage. Remake anysuspect joints ensuring a gas tightness check is carried out ifapplicable and the water system is correctly refilled, vented andre-pressurised.2. Proceed to “IMPORTANT”.CLEANING PROCEDURE1. Clean the main burner. Refer to Section 3.4.2. Clean the heat exchanger & condensate trap/siphon. Refer toSection 3.5 & 3.6.3. Check the main injector for blockage or damage. Refer to Section 3.3.ALSO IF THE DHW FLOW RATE IS IN QUESTION:4. Check the DHW filter for blockage.5. The cleaning procedures are covered more fully in Sections 3.3 -3.7 and MUST be carried out in sequence.6. Proceed to “IMPORTANT”.Do not operate the boiler if the front panel is not fitted.IMPORTANT1. If, for any reason, the condensate trap/siphon has been removed,ensure the trap is refilled with water before re-assembling.2. After completing the servicing or exchange of components alwaystest for gas tightness.3. When work is complete the front panel MUST be correctly refitted,ensuring that a good seal is made.4. Complete the service section in the Benchmark CommissioningChecklist.SERVICING