Vaillant ecoTEC plus 937 Instructions For Installation And Servicing

Also see for ecoTEC plus 937: Operating manual Operating manual Instructions and maintenance instructions

Contents

59ecoTEC plus 937 installation and maintenance manual• Pull the plug (4) out of the gas valve.• Pull the plug (3) out of the fan.• Unscrew the three screws (2) out of the thermo-compact module (1).• Remove the complete component group "gas valve/fan".5Fig. 9.3 Gas valve/fan screwed joint• Release both fixing screws (5) on the gas valve andremove the fan from the gas valve.• Replace the faulty component.a Caution!Danger of damage to the equipment!Fit the gas valve and fan in the same positionas before.• Screw the fan onto the gas valve.Use new seals.• Re-install the complete "gas valve/fan" unit in reversesequence.• After completion of the work check the system for gasleaks and carry out a function test (see Section 7.8).9.4 Replacing the expansion vesseld Danger!Before replacing components ensure that thesafety instructions from Section 9.1 areobserved.• Disconnect the appliance from the mains as describedin Chapter 9.1, and close the gas isolation valve in thegas supply pipe.• Close the isolation valves in the flow and return pipesand drain the water out of the combi boiler.1234Fig. 9.4 Replacing the expansion vessel• Unscrew the nuts (4) from the water pipe on theunderside of the expansion vessel.• Unscrew the two screws (1) in the retaining plate (2)and remove the retaining plate.• Pull out the expansion tank (3) forwards.• Guide the new expansion tank back into the appliance.• Re-connect the new expansion tank using a newgasket.• Re-fit the retaining plate.• Check the pressure of the expansion tank (minimumpressure 0.75 bar).If required, match the pressure to the static head ofthe heating system.• Fill and vent the combi boiler.• After completion of the work check the system for gasleaks and carry out a function test (see Section 7.8).Replacing components 9