Where it goes
The filter goes on the water main after the meter, before the pipe branches off to the rest of the house. On most homes that means an outside wall near where the main comes in. It's best kept out of the afternoon sun, because sunlight wears out plastic housings. A whole-house system usually has isolation valves either side and a bypass, so the filter can be shut off and the house still has water while a cartridge is being changed.


