Vaillant Evaporator 5kW 0020190059

The Vaillant evaporator, part number 0020190059, is a 5kW evaporator coil used in the outdoor unit of the Arotherm VWL 55/2 A 230V air source heat pump. It absorbs heat from the outside air into the refrigerant circuit, which the rest of the heat pump then upgrades and transfers to the heating and hot water system. It is a refrigerant-circuit component and is fitted within the outdoor unit casing.

• Reduced heating output or the heat pump failing to reach its usual flow temperatures
• Frost or ice building up on the outdoor unit coil and not clearing during a defrost cycle
• Refrigerant-side fault codes or low-pressure errors logged by the appliance
• Visible damage, corrosion or leakage on the evaporator coil
• Abnormal noise or vibration from the outdoor unit during operation

• Confirm the appliance model and, where possible, the serial number against the manufacturer's parts list
• Check that the existing evaporator is the 5kW variant and that the part number matches 0020190059
• Verify the fault is traced to the evaporator rather than another refrigerant-circuit component before ordering
• This is a refrigerant-circuit part — work should be carried out by a competent heating engineer with the relevant refrigerant handling qualifications