How to Bypass a Whole House Water Filter

Author: Rory Mullan - Published: 2022/02/04 - Updated: 2022/11/22

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You installed a whole house water filter to access clean water at home; what’s up with turning it off?

Filtered water is ideal for drinking, cooking and other purposes, but perhaps it’s not wise to utilize it for everything water-related you do.

So what can you do about it? A bypass valve offers a solution!

Besides, installing a bypass on your home water filter provides many more benefits, like hassle-free filter replacements.

So, here is our guide on how to bypass a whole house water filter.


  1. First decide where to place the whole house water filter.
  2. Close the water main.
  3. Cut into your main water line.
  4. Before installing the filtration system, install the bypass.
  5. Turn the water back on and check for leaks after.

Whole House Water Filter Bypass: What is it?

A whole house water filter bypass diverts water around your filter. In other words, the setup lets you shut down your water filter without interrupting water flow to your house.

As a result, you can still access unfiltered water when you turn off a.k.a. “bypass” your water filter.

But how can you use a bypass? Well, it depends entirely on the type of bypass.

Generally, a 3-valve bypass allows you to change the lever position of said valves. As soon as you do that, your filtration system bypasses. It remains in this state until you turn the valves to their initial positions.

Why Use a Whole House Filter Bypass Anyway?

You’re exposed to tons of water impurities and contaminants regardless of whether you’re on well or city water.

For this reason alone, most homeowners prefer installing a quality water filtration system. A whole house filter can successfully remove many harmful pollutants from water, making it fit for residential use.

As such, one might wonder about the purpose of installing and using a filter bypass in the first place. We’ll explain the science behind it.

Uninterrupted Water Flow

trickling faucet

Filtered water is excellent when cooking or otherwise consuming water. However, your plants do not need filtered water, just like other parts of your household.

Bypassing a filter is a perfect way to let your system rest for a while.

What’s more, it won’t disrupt water flow inside your home, which is great.

Also, when you do not use filtered water unnecessarily it prolongs your system’s lifetime.

Simply put, limiting filtered water usage means fewer filter replacements.

Easy Maintenance and Repairs

If you use filtered water, perhaps you know each whole house water filtration system needs proper maintenance to keep it up and running. For example, cartridge-based systems require frequent replacements to keep working effectively.

This is where a bypass comes in handy.

If you do not have an external or internal filter bypass, you would need to turn off the water supply to your entire house when replacing filters.

While this seems like enough trouble for replacing or servicing a system, what if a broken filter part would require you to send it away? This could potentially leave you without filtered water for weeks.

A whole house filter bypass guarantees continuous water flow throughout your home.

Installing a New Water Line vs. Bypassing

A few people consider installing a new water line instead of bypassing their filter. However, it’s not an ideal solution. Here’s why:

First, installing a new raw water line is not a straightforward DIY job. You might need a professional to do that for you.

For that purpose, you’re required to pay a hefty amount for labor work and also the materials needed for installation. In the end, you’re paying a pretty penny for a procedure that can be made simpler with a bypass.

Bypassing water filters is cost-effective and needs little DIY work. Also, it saves your time.

Whole House Water Filter Bypass – How Does it Work?

A bypass valve allows you to divert water around your water filter. As such, you can turn off the water filter and still access uninterrupted flow of unfiltered water.

This, in turn, reduces pressure on the filter components and benefits you as well.

With a bypass valve, you’ll have access to water no matter what. Yes, it will be unfiltered, but it’s water nevertheless, and you can utilize it for washing and other purposes. So, it’s better than having no water at all.

Generally, a whole house water filter system bypass contains three ball valves. The right and left valves are open while the center valve is closed. When bypassing the filter, you need to close the right and left valves and open the one in the center.

Side note: You can operate a bypass without right and left valves, too – and it will work. It’s just that the additional valves enable separating a filter from the home plumbing when required.

Step by Step Installation Guide: How to Bypass a Whole House Water Filter

How to Bypass a Whole House Water Filter Thumbnail

Whole house water filters often come with fitted bypass valves.

However, some don’t which can be an issue for people that want a bypass but don’t know how to realize that.

If you are uncertain about the installation process, we got you covered!

Below, we’ll explain the nitty-gritty of installing a whole house filter bypass. That said, you do not need to be a professional to get the job done; basic DIY knowledge should be enough.


Before getting started, it’s imperative to select the type of bypass you want to install.

In all honesty, building a 3-way valve with existing house pipes is the best alternative to fitted bypass valves. So, if your filter doesn’t have one, you better go with this option.

You would need some supplies and tools for installation.

First, you need to choose an appropriate pipe material to connect to your current pipeline. PEX, copper, and PVC are a few commonly used pipe materials.

After selecting a suitable material, you need to look for the fitting type.

Generally, solderless fittings are easy to attach, while soldered connections need extra steps to hook them up.

Lastly, you require 3 ball valves.

Gathering Tools and Supplies

Below, we’ll share some general tools needed to install a whole home filter bypass. Remember, the tool list differs depending on your filtration system and the bypass type you want to set up.

  • Torch
  • Valves
  • Solder
  • Hacksaw[1]
  • Fittings
  • Sandpaper
  • Flux
  • Piping
  • Reaming tool

Step-by-Step Installation Instructions

You can follow these step-by-step installation instructions for bypassing your water filter:

1. Choose Location

You need to choose a suitable location for a whole house water filter bypass. Where exactly do you want to have it?

If you already have your water filter installed, you’ll certainly go with that location.

2. Align Parts

Tech-savvy people recommend pre-assembling all the parts before performing any task, and bypassing a filter is no exception.

It’s best to gather all the parts for a smooth installation procedure. Running into a missing piece during the process is pretty frustrating.

3. Mark Pipes

Measuring twice is always a better option as it reduces the chance of errors. So, to make the installation process trouble-free, make sure you mark your pipes.

Yes, valves differ in length, but the product details explain the accurate measurements.

4. Turn off Water Supply

Turning off the water supply is something you’re naturally expected to do during installation, and it’s equally important too.

The installation process can take around 1-2 hours, and running out of water is not something you’d want, particularly if you have more people in your home.

Therefore, it’s best to ensure you have sufficient water for bathroom use or drinking.

5. Cut Pipe

Make sure you clean your existing pipes before proceeding. This is typically essential for copper pipes. It’s best to clean them properly before cutting.

You might want to cut the pipe near the main shutoff valve. However, there are no hard and fast rules regarding this. If you have your filter manufacturer’s instructions available, it’s best to refer to them and cut the pipes accordingly.

Additionally, do not forget to keep a bucket handy to collect all the extra water.

Your manufacturer can best guide you about the right way to cut the pipe. This will allow you to remove the pipe length required for appropriate fitting.

At this point, you can also use sandpaper or a reaming tool to scrub and clean pipe edges. It will eliminate leftover dirt and debris, which may otherwise corrode the pipes or cause leakage.

plumbing wrench ball valve brass connectors

6. Turn on Water Supply

Lastly, attach the right fittings to each end of the existing pipe. Secure everything tightly and adjust the valve.

Follow the same process for the other valves, and you’re all set. After connecting all valves, turn on the water supply and check for leaks.


A whole house water filter bypass guarantees uninterrupted water flow to your home when the filtration system is out of order or being serviced.

Bypassing can also make sense when you’ll be using a large amount of water that doesn’t need to be filtered, such as when you’re about to water your garden.

What’s more, a bypass makes filter maintenance much easier.

A proper bypass uses 3 valves to conduct water flow as required.

If you want to install a new bypass on your whole house water filter, prepare by gathering the necessary tools and equipment. Then follow our step-by-step installation guide: Choose location, align parts, mark pipes, turn off water supply, cut pipe and install, turn on water supply.

Further Reading


Meet Rory Mullan

Rory Mullan Rory has joined the Water Masterz team as a contributing writer. He has covered all sorts of topics in the last several years.

Outside of his writing work, Rory enjoys photographing the Irish landscape and making music!

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