As mentioned, It is the original Carver Cascade Mk1 water heater 1979-84. In many respects the best but flued through the floor and ABI introducing composite floors in 82 meant the need to flue through the wall, hence its premature demise and the arrival of the Mk2 Cascade in 85
http://www.arcsystems.biz/manuals/cascade1.pdf
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.