So with this in mind and back to my original question what controls are recommended?
I have also been looking at water softeners. Viessmann have said it is ok to fill the system with softened water so no need for a separate supply before the softener for the filling loop. However, most of the water softenerrs I have looked at have either 15mm or 22mm connections. Bearing this in mind what will the benefit be of having a bigger mains pipe feeding the house if the pipe is then reduced when it gets to the softener?
I have also been looking at water softeners. Viessmann have said it is ok to fill the system with softened water so no need for a separate supply before the softener for the filling loop. However, most of the water softenerrs I have looked at have either 15mm or 22mm connections. Bearing this in mind what will the benefit be of having a bigger mains pipe feeding the house if the pipe is then reduced when it gets to the softener?