Applies to: MODEL 903.663 with CODE (ZV1) Minibus Group 15 Heatmatic with/without circulation pump MODEL 904.663 with CODE (ZV2) Minibus Group 18/21 Heatmatic with/without circulation pump MODEL 903.662 /663 /672 /673 with CODE (ZV3) Minibus Mobil Heatmatic with/without circulation pump MODEL 903.662 /663 /672 /673 with CODE (ZV4) Minibus Taxi Heatmatic with/without circulation pump MODEL 903.672 with CODE (ZV6) Minibus VIP Heatmatic with/without circulation pump MODEL 904.663 with CODE (ZV5) Minibus Tourist H