Vaillant ecoTEC plus 937 Instructions And Maintenance Instructions

Also see for ecoTEC plus 937: Operating manual Instructions for installation and servicing Operating manual

Contents

33Installation and maintenance instructions ecoTEC plus 0020031552_03• Check that both stop valves on the combi boiler areopen.• Connect the filling loop as described in Section 5.4.2.• Open the water stop valve.• Slowly open the isolator valve in the filling loop sothat water can flow into the heating system. Bleed theradiator at the lowest point until water flows out ofthe bleed valve without bubbles.• Bleed all other radiators until the heating system iscompletely filled with water, all bleed valves havebeen shut and the manometer pointer is in the centreof the dark grey area. Bleed the heating pump by loos-ening the central screw. Close the filling loop valveand the cold water stop valve.• Loosen the cap on the automatic air vent by a coupleof turns. (In continuous mode the unit is vented inde-pendently by the automatic air vent system.)• Check all connections and the entire system for leaks.5.5 Initial flushing of the system ("cold“)h NoteThe entire heating system must be flushedthrough completely at least twice: once coldand once hot, in accordance with the followinginstructions.• Check if all radiator thermostat valves and both stopvalves on the combi boiler are open.• Connect a hose to the drain valve which is located atthe lowest position in the heating system.• Open the 1/2“ drain valves and all the bleed valves onthe radiators so that the water flows quickly and com-pletely out of the heating system and the combi boil-er, in order to remove the contamination caused dur-ing the installation out of the heating system beforethe combi boiler is started up.• Close the 1/2” drain valves and radiator bleed vavles.• Re-fill the heating system with water as described inSection 5.4.3.• Check that the pressure relief valve in the heatingsystem is functioning correctly by turning the handleon the valve.• Check the pressure in the heating system and top upwith water if necessary.• Close the filling loop valve and the cold water stopvalve.5.6 Filling the condensate siphond Danger!If the condensate siphon is empty during opera-tion of the combi boiler there is a danger thatexhaust gases can flow into the room andcause poisoning. For this reason you mustmake sure that the siphon is filled up everytime the unit is cleaned.• Remove the lower section (1) of the condensatesiphon by turning the bayonet connection in a coun-terclockwise direction a quarter of a turn.• Fill the lower section with water until about 10 mmbelow the upper edge.• Replace the lower section of the condensate siphon.1Fig. 5.4 Filling the condensate siphon5.7 Setting the pump outputOnly in ecoTEC plus appliances:The output of the two-speed pump can be matched tothe requirements of the heating system. If required,change the pump output, depending upon the setting ofthe operating mode, under diagnostic number "d.19“(see Section 8.1.2).5.8 Adjusting the bypassThe appliance is equipped with an adjustable bypassvalve. The pressure can be set between 170 and350 mbar. The valve is pre-set to approx. 250 mbar(mid-position). Each turn of the setting screw changes thepressure by approx. 10 mbar. The pressure is increased byturning to the right and reduced by turning to the left.1Fig. 5.5 Setting the bypass valve• Setting the by-pass valve using the setting screw (1).Commissioning, Part I 5