The Faucet-Mount Filter Is an Owner Job Until the Threads Don't Match: Check the Fit Before You Buy

A faucet-mount filter is one of the few water treatment jobs most homeowners can finish in an afternoon with basic hand tools. The job is only easy when your faucet cooperates, though. Before you choose between doing it yourself and paying someone, check the faucet and the adapter.

Check the faucet before the filter

Look at the spout tip. Most faucet-mount units screw onto a threaded aerator, the small mesh screen at the end of the spout. Find out whether the thread is standard male or female, whether the aerator unscrews by hand or with a wrench, and whether the spout is tall enough to clear the filter head. Pull-down and pull-out faucets often need a different adapter or a diverter part that the basic kit does not include. Write down the faucet brand and model, then compare them against the adapter list the filter maker publishes. If your faucet is not named on that list, stop and get an answer before you buy.

What the owner can do

If the threads match and the aerator comes off, the install is usually owner work. Remove the aerator, thread on the adapter, attach the filter head, run the water to flush the cartridge, then check every joint for drips while the water runs. Run water through the filter for the length of time the maker's instructions name before you drink from it. Keep the instructions and the cartridge model number with your receipt and any warranty paper.

When hiring makes sense

Call a plumber or a water treatment installer if the faucet has a built-in filter, a hot-only spout, an aerator that will not release without damage, or corroded threads. A pro is also worth the call if the filter needs its own shutoff valve or a line tapped under the sink. At that point the job is no longer a faucet job, and both the skill level and the cost change.

Decide before you open the box

Ask three questions. Do the threads and adapter match the faucet in front of you? Is the sink's water flow steady enough that a small mount unit will not be strained? Are you willing to check the connections again after the first day of use? If all three answers are yes, do it yourself. If any answer is no, compare a pro visit against a different filter style that fits your faucet.