The effect of volume and temperature of pre‐rinse water on the cleaning efficiency of five circulation cleaned recorder milking machines was investigated. A hot (>75 °C) pre‐rinse gave the lowest bacteriological rinse total colony counts. As the rinse count differences were small, the least expensive cold water pre‐rinse is considered satisfactory for most farms. A pre‐rinse volume of 16 litres per unit removed more residual milk than eight litres per unit but gave no significant difference in rinse counts. For most plants 8–10 litres per unit is considered a satisfactory pre