To comply with manufactures warranty terms & conditions all models should be fitted to an in-line water treatment (softener) system. NB limescale problems are not covered under warranty, callouts & repairs will be chargeable.
To comply with the manufacturer’s warranty terms, and for your own health and safety, all commercial gas appliances must be installed by a certified gas safe engineer, who is registered to install commercial appliances. Please note most ordinary plumbers and gas fitters are not covered to do this work!