Heat exchanger

A heat exchanger (76) for exchanging heat between first and second fluids, comprises an elongate housing extending parallel to a longitudinal axis of the housing. A stack of heat exchanger plates is received within the housing and supported such that a space is defined between each adjacent pair of plates. Each plate extends in a direction parallel to the longitudinal axis, and seals are defined at edges of the plates such that one space of each adjacent pair of spaces communicates with an inlet and outlet of the first fluid and the other space of the pair of spaces communicates with an inlet and an outlet for the second fluid. One inlet and one outlet are located at each end of the tubular housing. The housing is a sliding fit in a carrier tube (75) one end of which supports an electric motor (77). The carrier tube is a sliding fit in an outer support tube which in use extends between inner and outer faces (69, 70) of a wall, and the motor is supported by the carrier tube so as to project from the outer end of the support tube. Wires for energising the motor extend along the length of and are supported by a wall of the carrier tube such that the wires are protected against contact with either the housing or the support tube, the wires terminating at a connector mounted on the end of the carrier tube remote from the electric motor. The wires are embedded in grooves formed in the wall of the carrier tube (75).