The engine house is Grade II listed and was built to contain the original beam engine that pumped water from the reservoirs up to the higher level of the feeder river. It has been in continual operation since 1823, though in 1936 the beam engine was dismantled and replaced by the electric pumps. You can see the in-fill brickwork where the chimney was removed, marking the arrival of electricity. The building is typical of an engine house; one tall narrow room for the beam engine and lower storey ancillary rooms surrounding it. For this particular engine house the lower storey extension was added post 1846, when the canal was taken over by the Great Western Railway Company due to the decline of canal usage. This is telling in other details such as the workshop bench made out of railway sleepers and the reclaimed platform edging bricks on the stairs. The wooden beams for the upper floors are visible in between the brickwork and you can also see the structural ties that were added after construction, as the building needed more support to cope with the vibration of the machine.