Water filtration installation: what to know

What the job involves, what changes the price, and what to ask a pro.

What water filtration installation is

Water filtration installation adds a filter at the kitchen tap, under the sink, or where water enters the home to reduce contaminants. The filter type is chosen from a water test, since a sediment filter, a carbon filter, and a reverse osmosis system each handle different problems.

Signs you need it

  • Your water has an odor, a chlorine taste, or a color that you want removed at the tap
  • A water test shows contaminants such as lead, sediment, or chemicals that you want to reduce
  • Your well water shows sediment or iron, and you want the household supply treated
  • You want clean drinking water at one tap without changing the whole house
  • Your home has a water heater or appliance that is affected by sediment in the supply

What the pro does

  • Review the water test and choose the filter type: sediment, carbon, reverse osmosis, or a combination
  • Pick the install point: under the sink for drinking water, or at the main line for the whole house
  • Install the filter head or housing with the right fittings and an isolation valve, so the filter can be serviced
  • For reverse osmosis, run the drain saddle and the air gap, and connect the storage tank and the faucet line
  • Flush the filter and the lines as the manufacturer requires, and check for leaks at every joint
  • Set the filter change schedule, and give the customer the cartridge model and the replacement reminder

What changes the price

Every job is different, so we do not publish prices. These are the things that move the quote up or down.

  • Filter type and stages: sediment, carbon, reverse osmosis, or a whole-house system
  • Point of install: a single tap, an under-sink location, or the main line
  • Whether a new faucet or a dedicated tap is needed for the filter
  • Drain connection for reverse osmosis, and whether an air gap must be added
  • Electrical work for a booster pump or a UV unit, if one is chosen
  • Access under the sink or at the main line, and the piping that must be run

What a written quote should spell out

  • Filter type and stages, with the cartridge model and the replacement schedule
  • Install point and the fittings, shutoffs and isolation valves used
  • Drain connection and air gap for reverse osmosis, if it is included
  • Flushing and leak test, and what the customer must do afterward
  • Water test before the install, and a retest if the scope calls for one

Questions to ask before you hire

  • What does my water test show, and which filter stage handles each problem?
  • Are the replacement cartridges easy to get, and how much upkeep does the system need?
  • Where will the filter sit, and can I reach it to change it?
  • For reverse osmosis, where does the drain go, and is there an air gap?
  • Will you test the filter after install to confirm it is working?
  • Are the filter's certifications listed for the specific contaminants in my water?

Red flags

  • Pro who installs a filter without a water test to choose the stages
  • Pro who connects a reverse osmosis drain without an air gap or a proper drain saddle
  • Pro who says one filter removes everything without naming the contaminant it treats
  • Pro who does not flush the filter or test it for leaks after install

What you can do yourself

A homeowner can install a simple faucet filter that mounts without cutting any line, and can change the cartridges on schedule. Call a pro for a reverse osmosis unit, a whole-house system, or any work on the main line, since a leak at the main or a drain connection can flood the cabinet or the house.

Licenses and permits

Filtration installation that ties into the water supply or a drain is commonly licensed plumbing work, and a simple faucet filter is sometimes installed without a license. Check with your state or local licensing agency about what applies to your install.

Water filtration installation questions

Which filter do I need?

It depends on the water test. A sediment filter handles particles, carbon handles taste, odor and some chemicals, and reverse osmosis handles more dissolved contaminants. A pro should choose the stages from the test results.

How often do the cartridges need changing?

It depends on the filter type and how much water passes through it. The manufacturer's schedule is the starting point, and the pro should set a reminder for the first change.

Does a filter make the water safe to drink?

It reduces the contaminants the filter is certified for. Check the certification for the specific contaminants in your water, and retest after install to confirm the result.

Why does my reverse osmosis unit drain so much water?

Reverse osmosis produces waste water as part of the process, and the drain flow is normal in many systems. The pro can check the flow and the setting if the drain seems excessive.

About this guide

This national guide is written and checked by infinibell. Rules and conditions differ by place, so local pros are credited on guides for the cities they serve, not on national ones.

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