84 OperationInstructions for use ecoMAX84.4.2 Setting the external controlsFig. B.9 Setting the external controls• Set the room thermostat and/or the thermostaticradiator valves according to the instructions suppliedwith the control(s).Note!Vaillant offer room thermostat/time controlaccessories which give accurate and economicroom temperature control as well as improvedcomfort.Ask your installer!The boiler will now operate automatically to provide cen-tral heating for the conditions selected on the externalcontrols (ecoMAX 800 series will also provide domestichot water on demand).Whilst the boiler is operating, the boiler display indicatesthe temperature of the water within the boiler circuit.After the boiler stops operating the pump and fan willcontinue to operate for a short period to fully dispersethe heat from the boiler.Note!The boiler incorporates an anti-cycling economi-ser control to prevent energy wasteful ON andOFF operation of the boiler for short periodswhen in the central heating mode. When turningthe room thermostat to a higher setting theremay therefore be a short delay before the boileroperates.4.5 Status displays (Fig. B.10)(for maintenance and servicing work carried outby a qualified service engineer)Fig. B.10 Status displays• The status displays are activated by pressing the "i" (1)button.The display (2) now shows the corresponding statuscode, e.g. "S.4" for burner operation. Please refer totable B.1 (below) for details of the most important statuscodes.• Press the "i" button again to return to normal mode.During changeover phases, such as when the systemrestarts after the flame has been extinguished, the "S"status message is displayed briefly.Display MeaningS. 0* No heat requirementS. 1* Pump runningS. 3* Heating system ignitionS. 4* Burner ignitedS. 5* Fan and pump overrunS. 7* Pump over runS. 8* Anti cycling mode (after heating operation)S. 10** Hot-water demandS. 14** Burner ignitedS. 34* Frost protection modeTable B.1: Status displays (a complete list of status codes canbe found in the installation and maintenanceinstructions)* Heating mode** Hot-water mode (ecoMAX 800 series only)2134