How to install a whole house water filter

Whole house water filters are complex pieces of equipment, but setting up and maintaining your system shouldn’t be a grueling task.

Here are some tips to ensure a smooth installation of your new filter.

See our top picks of well water filters if you haven’t already made your purchase.

well water filtration system diagram

Installing your whole house water filter

#1. Use buckets and trays to catch leaks

Turning off your water at the main shut-off and draining your system before beginning installation is a must. Use the lowest faucet in your home to let water and pressure escape.

Even after this, however, small leaks are likely to occur as you set things up and check everything is correctly aligned. Protect your floor and maintain a safe working environment by placing buckets or trays underneath major connections and places where filter components are threaded together.

(Extra tip: leave the nearest faucet to the filter open during installation to allow any residual water or air to escape.)

#2. Leave room for a sediment filter and conditioner

Almost everyone who needs a whole-house filter for their well will also want a sediment filter to remove small particles before the water reaches the more delicate filter elements. Using a sediment filter will contribute to water purity and prolong the lifespan of expensive filter stages.

Because groundwater is naturally harder than surface water, many well owners also add a well water softener or conditioner alongside their filter system. So if your system doesn’t already include these things, try to leave room for them in case you decide to add them at a later point.

Remember that you’ll need room to access your filter periodically to check for leaks and change filter cartridges. Try to find a spot with sufficient space along the main water line before it branches to the various appliances in your home, and also allows for mounting the system to a wall or floor joist.

#3. Include a bypass valve

Installing your filter and/or softener on an additional line that can be bypassed with valves gives you the option to disconnect your filter without turning off the water supply to the rest of your home.

A bypass valve can make the process of changing filter cartridges less tiresome—especially if you go the extra mile and also install shut-offs between each filter stage so that you can isolate individual parts of your system.

Sediment filter screens often need to be cleaned or switched out every few months, while carbon filters require annual or biannual replacement.

#4. Flushing and checking for leaks

When your new filter system is connected, turn the water back on to flush the system out and check for any leaks.

Sometimes, slightly dripping from the filter casings compression fittings can be simply fixed with careful tightening. With more significant leaks, components may need to be taken apart and reconnected with great precisions.

Popular hacks for solving leaks include wrapping Teflon tape around the threads, greasing them, or using extra O rings.

Flushing your filter system will help to clear any dust or residue from manufacturing and installation, as well as prime the filter cartridges. Carbon filters, in particular, can require extensive flushing and may produce small pieces of black charcoal for hours or days, as air in the carbon block is replaced with water. This is normal and safe.

Once water is running clean and clear without air bubbles, your system should be running at full efficiency.

#5. Don’t be shy to call in a professional

Many people decide against DIY installation and instead reach out to a professional to fit their new filter system. Some manufacturers and suppliers will also offer installation services when you purchase the system, and many plumbing companies have a filter fitting service.

Always use licensed professionals when installing filters, drilling wells, servicing heaters, or commissioning any other plumbing jobs on your property.

Selection or tools (image from Unsplash)

Maintaining your whole house water filter

#6. Test your water regularly

Many water contaminants are undetectable by taste and smell, so an annual water test is the best way to know whether or not your filter is performing to expectations. This is especially important if you’re filtering water from a private well, or another unregulated source that may contain pathogens.

You can pick up a basic home water test online or from any large hardware store. Alternatively, send a sample off to a state-certified lab to get an official report on your water quality.

#7. Cleaning tanks

Many modern filters have auto-backwashing programs and other features to help keep non-changeable filter elements clean. Sometimes, however, it’s necessary to manually clean your filter tanks.

If a filter system has been left unused for several days or more, or if you suspect microbiological contamination, your should clean filter tanks via a combination of flushing and sanitization solutions.

There are premade NSF-certified sanitization solutions available, or you can mix a capful of white vinegar per gallon of water to create a homemade version.

To flush a water filter system, run water through all faucets and outlets for a minimum of five minutes. This helps to ensure that any contaminants are washed through.

When cleaning or flushing your system, it’s also a good idea to replace any changeable filter media.

#8. Look for deals on filter cartridges

Most filter papers and cartridges will last unused for a long time when stored in a cool, dry place. So it’s worth stocking up on supplies if you come across any sales or discounts.

Remember that you’ll need to refill or change out most filter media every few months—sometimes sooner depending upon water quality or contamination events. As one Reddit user says, “I use GE paper filters which I buy in bulk from Amazon. I change the filter every three months and I refill the salt in the softener about once a month.”

#9. Shock chlorinating

The large amounts of chemical disinfectant used during shock chlorination mean that you need to be careful to avoid spillages and not to leave chlorine circulating through the water system for too long.

Using too much bleach or leaving it in the well risks causing corrosion, weakening casing and pipes, and infecting drainage systems. Most sources recommend using no more than two quarts of chlorine bleach per every ten gallons of water.

#10. Don’t forget about the well

For those running a whole-house water filter for well water, it can be easy to focus on maintaining the filter system, and forget about the physical well in your backyard.

Try to keep any chemical-containing products like paints or pesticides far away from the location of your well in case of spillages. Also remember to keep the well lid at least 16 inches above the ground, ideally with the ground sloping downwards away from the well, in order to discourage surface runoff.

As part of your general maintenance routine, perform inspections of your well lid and casing to check for any cracks.

Bonus tips!

  • Check you have the fittings you need before starting an install

Noticing that a one-inch pipe connector is missing from your filter system before you begin fitting it means a little frustration and a trip to home depot. Noticing it’s missing 3/4 of the way through an installation means your home will be without water for hours longer than your anticipated.

  • Small leaks may be normal

Very small leaks (such as visible wetness around threadings) aren’t necessarily a sign of faulty components or installation errors. If you’ve tried fixes such as Teflon tape or even gluing components together, you may need to make do with leaving a tray or rag under that part of the system. That said, obvious dripping from a connection is not acceptable.

  • Use a pressure-reducing valve for delicate filters

Some properties are lucky enough to receive a highly pressured water supply. This is great news for your shower but less good for some types of filters, which may have maximum pressure requirements.

  • Don’t turn off your UV purifier

Many filter manufacturers and plumbers recommend not turning off UV purification systems during periods of disuse. If you are frequently turning the system off and on, you can end up dramatically reducing the lifespan of the lamp.