137 MAINTENANCEGabarrón electric boilers do not need any special maintenance, only the following should be checked:-Check the pressure indicated by the pressure gauge frequently, ensuring that it is between 1 and 1.5 bar when cold.- Never start the boiler when it is empty.- Never start the boiler when the S.H.W. tank is empty; to fill it for the first time open a hot water tap and wait untilwater comes out of it.-Precaution against freezing. In dwellings that are frequently unoccupied or at risk of freezing, an anti-freeze of theappropriate quality can be added to the water of the heating installation – the concentration must not exceed 30%in volume.- Clean the surfaces of the boiler with a damp cloth, having previously disconnected it from the mains. Do not usesolvents or abrasive products.8 TROUBLESHOOTINGProblem Possible cause SolutionBoiler will not start No current entering boiler. Check the installation.Error E1 Heating water out temperatureprobe defective.Contact Technical ServiceError E2 Heating water return temperatureprobe defective.Contact Technical ServiceError E3Lack of heating water flow.Pump blocked. Unblock – see instructionsValves shut. Open valves.Air in the installation. Purge the installationError E4Overheating of the heating.Pump blocked. Unblock – see Section 6.3.3.Valves shut. Open valves.Air in the installation. Purge the installation.Error E5 Configuration error of the maximumlimited output.See Section 5 LIMITATION OFOUTPUTError E6 S.H.W. temperature probedefective.Contact Technical ServiceError E7Overheating of S.H.W.S.H.W. tank empty. Open a hot water tap until the waterflows. See Section 6.4.2 S.H.W.Safety.Heating safety valve expels waterExcessive pressure in cold. Adjust to between 1 & 1.5bar.Expansion vessel breakdown. Change.Water entering heating circuit. Check filling valve.S.H.W. safety valve expels water. Entering water pressure too high. Install a pressure reducer.S.H.W. expansion vessel breakdown Change.The buttons do not respond Control panel blocked See Section 10.2 BLOCKING THECONTROLSLow temperature in the installation.Heating setting low. Regulate.Setting of ambient thermostat low. Regulate.Resistances broken down. Contact Technical Service.Badly calculated installation. Increase output.After resolving the problem, in order to eliminate the error message on the display, it is necessary to switch theboiler off and on using the button.