Vaillant VWL 57/5 IS Operating, Installation And Maintenance Instructions

Also see for VWL 105/5 AS S2: Operating instructions Operating instructions Operating instructions

Contents

Appendix54 Installation and maintenance instructions Hydraulic station 0020257319_02Code Meaning Cause RemedyF.731 High-pressure switch open – Refrigerant pressure too high. Theintegrated high-pressure switchin the outdoor unit has tripped at41.5 bar (g) or 42.5 bar (abs)– Insufficient energy output via thecondenser– Purging the building circuit– Too low a volume flow as a resultof closing single room controls in anunderfloor heating system– Check that the dirt filter that is inplace is permeable– Refrigerant flow rate too low (e.g.electronic expansion valve defective,4-port diverter valve is mechanicallyblocked, filter is blocked). Informcustomer service.– Cooling mode: Check the fan unit fordirt– Check the high-pressure switch andhigh-pressure sensorF.732 Compressor outlet temperaturetoo highThe compressor outlet temperature isabove 130 °C:– Application limits exceeded– EEV does not work or does not opencorrectly– Refrigerant volume too low (frequentdefrosting due to extremely lowevaporation temperatures)– Check the compressor inlet sensorand outlet sensor– Check the compressor outlet temper-ature sensor (TT135)– Check the EEV (does the EEVmove to the limit stop? Use thesensor/actuator test)– Check the refrigerant volume (seeTechnical data)– Carry out a leak-tightness test– Check whether the service valves onthe outdoor unit are open.F.733 Evaporation temperature too low – Insufficient air volume flow throughthe outdoor unit's heat exchanger(heating mode) leads to an insuffi-cient energy input in the environmentcircuit (heating mode) or building cir-cuit (cooling mode)– Refrigerant volume too low– If the building circuit contains ther-mostatic valves, check that they aresuitable for cooling mode (checkvolume flow in cooling mode)– Check the fan unit for dirt– Check the EEV (does the EEVmove to the limit stop? Use thesensor/actuator test)– Check the compressor inlet sensor– Check the refrigerant volumeF.734 Condensation temperature too low – The temperature in the heatingcircuit is too low, outside of theoperating characteristics– Refrigerant volume too low– Check the EEV (does the EEVmove to the limit stop? Use thesensor/actuator test)– Check the compressor inlet sensor– Check the refrigerant filling volume(see technical data)– Check whether the 4-port divertervalve is in an intermediate positionand is not correctly switched– Checking the high-pressure sensor– Check the pressure sensor in theheating circuitF.735 Evaporation temperature too high – Temperature in the environmentcircuit (heating mode) or buildingcircuit (cooling mode) too high forcompressor operation– Feed-in of external heat into theenvironment circuit due to increasedfan speed– Check the system temperatures– Check the refrigerant filling volumefor overfilling– Check the EEV (does the EEVmove to the limit stop? Usesensor/actuator test)– Check the sensor for the evaporationtemperature (depending on theposition of the 4-port diverter valve)– Check the volume flow in coolingmode– Check the air volume flow in heatingmode