Vaillant ecoTEC sustain 24 Installation And Maintenance Instructions Manual

Also see for ecoTEC sustain 24: Operating instructions Installation and maintenance instructions

9 Troubleshooting26 Installation and maintenance instructions ecoTEC sustain 0020253094_019.7.2 Replacing the fan or gas valve7432169851. Remove the air intake pipe.2. Remove the plug from the gas valve (7).3. Remove the plugs (6) and (9) from the fan motor bypushing in the latching lug.4. Unscrew the connection from the gas valve (8).5. Unscrew the three screws (2)-(4) between the mixturepipe (1) and the fan flange.126. Remove the entire fan/gas valve unit from the product.7. Unscrew both fixing screws (1) on the gas valve andremove the fan from the gas valve.8. Replace the defective fan or the defective gas valve.9. Install the gas valve and the fan in the same position asbefore. Use new seals for this.10. Screw the fan to the gas valve.11. If you had removed the gas pipe, screw the cap nutof the gas pipe (2) only loosely to the gas valve. Onlytighten the cap nut on the gas valve after the installa-tion work has been completed.12. Refit the entire fan/gas valve unit in reverse order. Youmust use a new seal (5) for this.13. Ensure that the order in which the three screws arescrewed in between the fan and the mixture pipe cor-responds to the numbering (3), (2) and (4).14. Tighten the cap nut (2) on the gas valve and the capnut (8) between the gas pipes. In the process, securethe gas pipe against twisting. Use new seals for this.15. After you have completed this work, carry out a leak-tightness test (function check). (→ Page 22)16. If you have installed a new gas valve, adjust the gasratio setting. (→ Page 18)9.7.3 Replacing the heat exchanger1. Drain the product. (→ Page 30)2. Detach the condensate drain hose from the heat ex-changer.3213. Remove the clamps (2) and (3) from the area of theflow and return connection.4. Disconnect the flow connection.5. Disconnect the return connection.6. Remove both screws (1) from both brackets.217. Remove the lower three screws (2) on the rear sectionof the retainer.8. Move the bracket round to the opposite side and attachthe upper screw (1) to the side.9. Pull the heat exchanger downwards and to the right,and remove it from the product.10. Install the new heat exchanger in reverse order.11. Replace the seals.NoteInstead of grease, use only water or com-mercially available soft soap to aid installa-tion.