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How to Install a Water Filtration System

Use these step-by-step instructions to see how Ed Del Grande installs a water-filtration system throughout a house.

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Step 1: Choose a Filtration System

Have the water system tested by the local utility board to pinpoint the system that that will work best. There are three types of filtration systems to choose from:

  • Point-of-use water filter (goes to only one fixture and filters only that fixture) (Image 1)
  • Point-of-entry water filter (installed where plumbing enters the building and filters the whole house's water system) (Image 2)
  • Whole-house cartridge filter (like point of use) (Image 3)

    Tip from Ed: Even if the water is good, always install a point-of-use filter on the kitchen sink because it will make it that much better.

Step 2: Shut Off the Water Supply

When starting this project, find where the water comes into the house from the outside (sometimes in a basement). Shut off the water supply to the house and the water heater, then drain the outside and inside water that's left in the pipes by opening up the sillcock outside as well as a faucet inside.

Step 3: Build Two Setups

To prep the filter, it's necessary to build two setups. You will need a bushing, a nipple, a ball-valve and a compression male adaptor.

Wrap Teflon® tape around the adaptor and thread it through the bushing. Add more tape to the other end of the connector and attach it to the gate valve. Thread the compression male adaptor with the Teflon tape and connect it to the ball valve. Grip the front end of the fitting with the slip joint pliers and slide a wrench over the hex nut to tighten the assembly.

Repeat this process to create the second fitting.

Step 4: Screw the Fittings Into Each Outlet

Once the second fitting is complete, wrap Teflon® tape around the bushings and screw the fittings into each outlet on the filter head.

Again, use the slip joint pliers to tighten everything.

Step 5: Remove the Bottom Canister of the Filter

Now the filter is "dressed." Before figuring out where to cut the water lines and attach the filter, remove the bottom canister portion of the filter (it is awkward and bulky to hold) and hold up the top part of the filter to measure out the length of line that needs to be cut.

Step 6: Cut the Pipe

If there are any wires along the pipes, check with an electrician first to make sure it is OK to cut the pipes. Determine the best installation point by holding up the filter's head and mark where the filter should go on the pipe itself. Make the first cut on that line with a mini-pipe cutter. Some water may be trapped in the line, so keep a bucket handy to catch any falling water.

Place a copper T against the pipe to determine the next cut and remove the pipe. The bottom stub may have a bit of water left in it and if so, stick a piece of the copper pipe in the bottom stub and remove the water like a straw with your finger over the top.

Step 7: Position the T

Clean and prep a copper T and the two pipe stubs. Pull the stubs apart and slide the T into position. Then clean and flux a 2' section of copper pipe and push it into the open leg of the T.

Solder all the joints together and wipe away any excess solder with a rag.

Step 8: Cut the Pipe and Remove Burrs

After marking the spots for the loop and bypass valve, two cuts need to be made to remove the pipe. If there's water in the lines, drain it before making the next cut.

Now remove burrs from the cut section of pipe, a copper T, both ends of a ball valve, and two pipe stubs.

Step 9: Complete the Bypass Loop

Add flux to the ball valve and attach it to the stub pipe. Flux the cut section of pipe then insert it into the ball valve. Last, flux the T and slide it into place.

Complete the bypass loop by cleaning and fluxing a ninety degree elbow and the measured section of pipe. Slip the elbow onto the pipe and slide it into position (Image 1).

Check the loop for stability then fire up the torch and solder all the fittings together (Image 2).

Step 10: Mark the Installation Points

Use the filter head to mark the installation points. Leave a 1/2" space on one side to accommodate the pipe's entry into the bushing. Make the cuts and discard the pipe.

Step 11: Slip the Assembly Into Place

Take the compression nut with the brass ferrule and slide one on each end of the stub pipe.

Make sure the end marked "in" on the filter head faces the incoming water supply then slip the assembly into place.

Firmly tighten the compression nuts, first with your hands and then with two wrenches.

Next, shut off the incoming, outgoing and bypass valves. It's now safe to turn on the water at the main valve and check for leaks.

Step 12: Remove the Filter and O-ring, and Check for Leaks

Remove the filter and o-ring from the canister. Check for damage then return all components and screw the canister to the filter head. Do not over tighten the fitting. The unit is designed to seal by hand-tightening only.

After mounting the filtration system, check that the outgoing valve is off. Open the incoming valve, which allows water to enter the filter. Check for leaks then open the outgoing valve. This lets filtered water into your home's plumbing system.