Do you make a mixer shower that I can install onto a gravity hot water supply and mains cold water supply?

We do not recommend installing our mixer showers onto unbalanced supplies of this type. While most of our mixer showers incorporate a single check valve in each inlet there is always a risk that debris may enter the mixer and prevent the check valve in the hot inlet from sealing off. Should this occur mains water at pressure will flow into the hot supply forcing water in the cylinder back into the cold water cistern potentially causing water to overflow from the cistern and damaging property.