Bosch Aquastar 125 & WR400 Series Heat Exchanger

The Bosch Aquastar 125 Series Heat Exchanger Part #8705406380 (old part number 8705406235) is the replacement heat exchanger for all Bosch Aquastar 125 series and WR400 series Bosch tankless water heaters (regardless of Serial Number).  Astravan is a company in Canada that use to distribute the older Bosch WR400 series tankless water heaters.

Heat Exchanger Part #8705406380 (87054063800, 8-705-406-380-0) is the direct replacement for the following Bosch tankless water heaters:

125B, 125BO, 125BL, 125X, 125HX, 125FX and the following Bosch ProTankless water heaters: 425EF, 425HN (with serial numbers starting 685 and lower) and 425HNO, WR400-1KV1P23S3100, W400KD5  P23S3100T2, WR400-3K V1B23S3100, WR400-7K  V1G23S3195, WR430-3K  VM1E23S3190, WR430-3K  VM1E23S3195

The Bosch Heat Exchanger Part #8705406380 is NOT compatible with the following models:

125BS, 1600P, 1600H, 425PN, certain Bosch ProTankless 425HN (with serial numbers starting 686 and higher), 520PN, 520HN, WRS400K 1P23S3100T2.

Please call us at 888.726.9752 with questions or to place your order.