clock menu more-arrow no yes mobile

How to Install a Whole House Water Filter

Ask This Old House plumbing and heating expert Richard Trethewey improves the taste and odor of municipal drinking water with a whole house filtration system that includes a sediment filter and a granulated activated carbon filter

Steps:

  1. Turn off the main plumbing supply to the house and drain as much water as possible from the pipes by opening all faucets and fixtures and then opening a drawoff valve near the main.
  2. Determine the location of the prefilter. If necessary, attach a piece of plywood for attaching the filter bracket.
  3. Use a tubing cutter to cut in to the main water supply pipe.
  4. Clean, apply flux, and solder the adapter fittings to transition into the filter housing on a workbench to keep the heat away from the filter. Once cool, connect the adapter fittings to the filter housing, using thread sealing tape on threaded connections.
  5. Clean, flux, and then dryfit the remaining connections. Include “T” fittings that allow water into and out of the filter, but also connect to a shutoff valve that serves as a bypass. Include a shutoff valve for water entering the filter and a shutoff valve for water leaving the filter.
  6. In normal operation, the bypass valve remains in the closed position and the two filter valves are in the open position. If the filter requires service, those valves should be reversed, allowing untreated water into the building temporarily.
  7. Once all connections have been made, turn water pressure back on to the building and check for leaks.
  8. Follow manufacturer instructions to properly activate the carbon filter.