How to Install a Whole House Water Filter

Whole house water filters are a great way to rid the water in your home from contaminants, and ideal when you want clean water to in your bathrooms as well as the kitchen. Some of the best models can go for well over year before you need to replace the filters, but the installation process itself often keeps consumers from taking the plunge.

Whether you’re thinking about installing a whole house filter yourself, our guide has you covered. We’re going to walk you through the process of a whole house water filter installation from start to finish and give you an idea of what to expect if you decide to hire a contractor as well.

Are Whole House Water Filters Difficult to Install?

Not unless you have a “unique” plumbing system in your home. By that, we generally mean old plumbing which you may not know you have until you get ready to turn off the water. Any problems with your pipes should be addressed before you install your new whole house water filter or you could damage your system.

Take a look at your plumbing before you start the job, and set aside a day for your project. It may only take a few hours to install a simple two-stage system, but this isn’t the type of thing you want to rush. Also, consider your hydration and bathroom needs along with anyone else that will be home while you install the filter.

Due to the nature of their design, a whole house filter installation requires you to shut off the water to your “entire” home, not just one room. If you’re not handy with tools or plan to install a filter with a half-dozen stages, you may need a backup plan for bathroom breaks.

Installing a Whole House Water Filter

The first thing you should do if planning to go the DIY route is to read the instruction manual for your water filter system, which may include pre-installation steps for your filters. While the overall process largely remains the same, the steps to install a 5-stage system with dual tanks and a UV filter may be slightly different from someone that just has a two-stage filter.

With that in mind, our guide will walk you through the general process behind installing a whole house water filter system, and can help you fill in the blanks if you have a poorly written manual – they are quite common.

What’s in the box?

The last thing you want to do is make frequent trips to the hardware store when doing any project around your home. That means you need to check your kit to see what’s included, and what fixtures you may need to pick up. Some companies sell complete kits or Pro installation packages, which include everything you need, but you always need to check inside the box as well as the fine print.

More often than not, you will need to make a trip to the hardware or plumbing supply house to acquire a few things. While it varies, generally you’ll need a couple of shut-off valves, hex or pipe nipples, pipe unions, and possibly a ground jumper bypass valve cable. Depending on the installation method, you may also want or need pressure gauges or a. Thankfully, things are more straightforward when it comes to tools.

Tools of the Trade

Two tools you can’t do without are an adjustable wrench and pipe cutter. There’s a good chance you may have the former in your toolbox already, but a pipe cutter isn’t a traditional tool. The RIDGID 40617 is a good choice as it goes up to 1 1/8” and is made for tight spaces. For an adjustable wrench, Klein is a brand we highly recommend if you want a well-made tool. Hacksaws can be used if you have enough room for an even cut, but that may not be the case in your home.

Teflon tape, safety glasses, and gloves are also recommended along with a bucket and towel. Other optional tools include pipe hangers, silicone grease, and a drill or screwdrivers – all things that are affordable and easy to access. The most fearsome tool you may need to use would be a torch along with some solder, but again, it all depends on the system and the current plumbing in your home.

Choosing a Location for your Whole House Filter

When you have tools and supplies ready, and you’re sure you want to install a whole house filter yourself, it’s time to scout the perfect location. If you have a basement or garage, it may be overhead, but in older homes, the main water line can enter your home in a variety of ways.

The best place to install your filter is close to the junction where water comes into your home; after the shutoff valve but before the hot water heater. This allows the sediment filter to trap things before it hits your water heater while allowing you to receive filtered water on both sides of the tap. If you have well water, things are a bit different, so you’ll want to check out our well water section towards the end of our guide.

Installation Steps

  • Safety First

When you’re working on a kitchen or bathroom sink, you can shut off the water to a room or section of the house. With a whole house filter, you need to locate the shutoff valve for the main water supply to your home, and then turn off the electricity to your hot water heater. You also need to open your faucets to release pressure from the line and drain water, which you’ll be thankful for in our next step.

  • Measure twice, Cut once…

This is an area where it’s wise to consult your manual, which will give you the dimensions for your system. It’s also where you’ll want to plan for a bypass valve if you intend to install one in your chain. Take any mounting systems or brackets into account as well including the surface behind your filter as you may need to pick up tapcons or a piece of plywood depending on your situation.

Before you mark the pipe, keep fittings, pressure gauges and anything additional filtration in mind that’s not included with the system. That includes pre or post-filters along with UV filtration if you’re building your own system but using a whole house filter as the base. When ready, grab your bucket and towels, cut the pipe, and clean up any mess.

  • Assembly & Installation

After you’ve slid the pipe, you’ll want to install new shutoff valves on both sites of your filter. Then we highly advise you to lay everything out in front of you and use the dry-fit method to give it a test run. Essentially, you want to piece together any fittings or pipe to make sure it’s the right fit before you put anything together. Teflon tape should be used on any threaded pipe ends in your water system, which helps prevent leaks.

This allows you to catch any potential issues beforehand with valves, unions, or other parts. It’s wise to use a deburring tool or sandpaper on the end of any cut brass pipes to ensure a smooth fit, and you’ll want to check your filters and housings at this stage as well. On the off-chance there was an issue at the factory, it’s better to see it now than when you have 15 GPM flowing through your system.

When ready, check, and double-check all your ends, grease up any O-rings, and then put your system together as directed. Make sure the sediment filter is first in the chain unless you are installing an additional softner or pre-filter before that, and when in doubt, always check the manual. Even a bad manual will give you a diagram to go by, regardless of whether the instructions are legible.

  • Turn the Water Back On

After you are sure everything is tight enough and before you tighten up the housings, you need to consider any steps needed to prep your filters or system before firing it up. This is another area that will vary depending on your whole house water filter as you may need to soak carbon for 48 hours or do a surge flush on the system beforehand.

With most systems, you simply need to turn the water back on and check for leaks. You may need to connect a ground jumper wire in some systems; however, if you have an older home that uses pipes for a ground from the box.

When you first turn your water, do so slowly and don’t be alarmed by any sounds you hear as those will cease once the system is full. If you don’t see any drips, you’ll want to head over to a “cold” water tap that’s nearby and turn it on to flush the system. Only use cold water to flush your system.

Just like with a water filter pitcher, carbon dust may need to make its way out of the system before it’s ready to drink. In some cases, you may need to do it again after it rests for a period of time, but it will be evident when your H2O is clear instead of dark or cloudy. On that note, it can take a few days for the water in your hot water heater to become filtered unless you drain the tank.

Provided there are no leaks; your job is basically done but you should still check your system periodically for the first few weeks. Something as small as an ungreased gasket or forgetting to tape a pipe can cause issues down the line.

Installing a Whole House Filter for Well Water

If you have well water and aren’t installing your whole house filter on a municipal system, things are a little different. You still need the same tools and will follow the same basic steps we outlined above, but as you’ll have additional filtration, there are a few things to consider.

Well water presents its own set of problems, and while how people deal with those issues vary, the solution always involves a tank, pump, and a solid spin-down filter for sediment. Well water isn’t treated like municipal water at a plant, so chlorine doesn’t present the same issues.

That means if you have a water softener, you’ll want to install your whole house filter after the softener so you can make use of the full flow while backwashing. Whether you have acidic well water or need to reduce a heavy dose of lead, the first thing in your chain should handle sediment, and the last should be a UV filter for bacteria. Here’s a great example of a professional dealing with a whole house well water installation.

Professional Whole House Water Filter Installation

There are several advantages to hiring a professional to install your whole house filter. If you’ve never used a drill, you’ll want to call in a Pro as they can handle the job from start to finish. It’s also ideal if you have questions about your current plumbing or plan to add additional filtration into your water chain.

The price to install a whole house water filter is different from state to state, and a number of factors can affect the price. On average, you can expect to pay anywhere between $400 to over $1000 depending on what you need accomplished and how much they charge per hour if you call a plumber.

A general contractor may be cheaper and take the job at a flat rate; just keep in mind that some systems require a licensed plumber or you could end up with a voided warranty.  If you’re interested in hiring a pro, check out our pricing tool to get a quote in your area.


Final Thoughts

If you’re tired of bathing in over-chlorinated H2O or need to clean up water from your private well, a whole house filter is an outstanding investment. If you still haven’t settled on a system, our whole house water filter guide features several of the top systems money can buy. Whatever filtration method you choose, remember to check your water before and after installation to ensure the filter is working properly and performing as advertised.