Hot Water Geyser

My hot water geyser burst and was replaced on April 30 2019 by Bakgat plumbers Welkom, The installation was one to comply with Plumbing compliance standard SANS10254 which include 2 Vacuum breakers a new Temperature and pressure safety valve and a new Multi valve (pressure control valve) Also included in the installation (not required under Sans 210254) was a non return valve in the hot water line from the geyser to the taps in the kitchen and bath rooms. This valve in my opinion serve no purpose as there is absolutely no risk on water flowing back to the geyser from the taps. But according to the plumbers this valve is stipulated and required by the Insurance company. With the deteriorating infrastructure in Welkom we experience a lot of water supply interruptions to repair burst pipes. Each time this happens the hot water from the geyser siphon back into the coldwater supply draining a substantial amount a water from the geyser. There is a risk of damage to the geyser if the water level drops below the thermostat level and seeing that the installation is still under guarantee The Plumbing compliance Sans10254 standard supposedly have been drawn up to prevent this from happening. I contacted Bakgat Plumbers to come and have a look at the installation. Bakagat Plumbers advised me to submit a new claim to the insurer so that they can have a look at the problem. A new order number was issued Digicall FOGI Plumbing Solution the preferred provider of Absa Insurance to Bakgat Plumbers. The plumber assigned to the job after consultation with his foreman installed a non return valve in the cold water supply pipe before the water enter the Multi-valve. Obviously this is an easy solution to the problem instead finding which of the newly installed valves are faulty and replacing it This solved the problem and no further draining of hot water was experienced during subsequent interruptions of the water supply over the weekend.I am satisfied that the problem has been solved The problem is that I am now expected to pay for the installation of this non return valve which in my opinion should have been stalled in the first place. I am not prepared to pay to rectify a problem that was caused by an installation that is still covered under guarantee. If the SANS 10254 Standard is supposed to eliminate siphoning of hot water back into the cold water pipes than there is a faulty valve that needs replacing and if it is not drawn up to prevent that than a non return voave should have been installed in the cold water supply in the first instance.