The amount of flow you need (generally) dictates the size of the unit. The size of your house generally dictates how much flow you need. Screwfix carry a line of averagely reviewed ones that we used as an initial ballpark of size/vague cost of unit needed. Worth thinking about where you want to locate it alongside your water supply that can be adequately powered/accessed. That was the tough bit for us as our water supply comes under the back of kitchen cabinets, but the meter and stopcock are halfway down kitchen along the pipe run, which really limited where we could put in the unit.
It seems almost impossible to find a price online for them, they all appear to be sold by the equivalent of double glazing companies.
The amount of flow you need (generally) dictates the size of the unit. The size of your house generally dictates how much flow you need. Screwfix carry a line of averagely reviewed ones that we used as an initial ballpark of size/vague cost of unit needed. Worth thinking about where you want to locate it alongside your water supply that can be adequately powered/accessed. That was the tough bit for us as our water supply comes under the back of kitchen cabinets, but the meter and stopcock are halfway down kitchen along the pipe run, which really limited where we could put in the unit.
Very much felt this too.