A home water filter is a great addition to any home emergency kit. It’s the perfect complement to your backup water tank when essential supplies like water are restricted or contaminated in a natural disaster. If you’re like most people with water filters at home, you probably don’t think much about it. But if you want to keep your back up water supply tasting great and free of contaminants, you’ll need know how to change a water filter cartridge. Here’s a quick guide for an under sink water filter and a whole house water filter, along with what costly mistakes to avoid. No one wants a gigantic wet mess to clean up after all. So let’s get started!

Changing a water filter is easy (but it can go wrong quickly)

I was a little intimidated when it cam time to change my first water filter. My water had just come straight from the pipe before – no need to mess with anything!

Then I bought a house with a water filter installed.

Grateful as I was for the contaminant free water, I now had a whole house water filter on the wall in front of me. I had no idea what to do with it. I just knew it was time to change the water filter cartridge out.

When I looked closely at the water filter it seem straightforward. So I didn’t research any instructions and just jumped right in. Things quickly went downhill. As I unscrewed the chamber, water started spraying everywhere. I panicked. It took me forever to get the chamber sealed back in place and the whole thing cleaned up.

It was stressful! But it didn’t have to be!

Lessons learned: Instructions are your friend! Once I got across the steps, changing our water filter was a simple and painless process.

It’s easily something you can take on without the $180 plumbers fee. I have three different water filters at home that I change at different times of year.

So let us help you save some money. Here is the easy step by step for how to change your water filter cartridge at home. The steps are different for an under sink system and for a whole house system.

Don’t forget to read about the most common messy mistakes to avoid when changing your water filter cartridge. Nobody likes an unnecessary clean up!

Water filter parts you’ll need to know about

Here are 5 water filter terms need to know about, to change the cartridge in your filter (with pictures)!

The set up will be slightly different for an under sink system and a whole house system. But don’t worry, we are going to step through changing the water filter cartridge for both!

Mounting bracket – A water filter is commonly connected to your water pipes and mounted on the wall with a mounting bracket.

Housing / Chamber – this is the cylinder shaped container on the water filter that contains your cartridge.

Tool – some water filters come with a large plastic, ‘o’ shaped tool that helps you remove the housing from the mounting bracket.

Water inlet / outlet – you usually see two water pipes attached to the water filter system: the water inlet (water comes in from the main water supply) and the water outlet (water goes out of the filter to your tap(s).

Isolation valve – there is usually a valve (like a tap) to turn off the water to your sink. This same valve should turn off water to the water filter. In a whole house filter, the isolation valve may be on your pump or your main water line into the house.

Great! Know you know what you’re looking at, let’s get into the step by step process of how to change a water filter cartridge!

How to change an under sink water filter cartridge

An under sink water filter purifies the water that you use from the sink only. They are most commonly found inside the cupboard under the kitchen sink. They are usually sitting in or on a mounting bracket.

Things you’ll need

• Spanner to undo any nuts (depending on how the water filter housing is connected)
• old towel and shallow bucket for excess water capture.

Step by step

Here is how to change a water filter cartridge under a sink:

1. Turn off the water supply to your kitchen tap. The water filter should be connected between the tap and the isolation valve underneath the sink. Turning off the isolation valve will stop the water running as you change the water filter cartridge.
2. Turn on the kitchen tap until all water drains from the pipe. This will remove water pressure from the pipe between the water filter and the tap. You don’t want water rushing out as you disconnect the water filter.
3. Unscrew the water filter housing / chamber or unscrew the cap. The chamber will still have water in it, so hold the water filter upright as you unscrew the cap.
4. Tip out any remaining water and remove the old water filter cartridge. Discard it according to the manufacturer’s instructions.
5. Insert the new water filter cartridge into the housing unit and reattach to the mounting bracket. Some cartridges may also screw into the mount like this

6. Turn on the isolation valve under the sink.
7. Check the water filter housing to make it is sealed and no water is leaking out.
8. Turn on the kitchen tap to run some water through the filter for around 2 minutes. This will clear any air bubbles.

How to change a whole house water filter cartridge

Whole house water filter systems are usually located near the main water supply point for the house. If you have tank water supply, the water filter will be located between the pump and the main pipe into your home.

Things you’ll need

Water filter tool. Towel. Shallow bucket.

Step by step

Here is how to change a water filter cartridge for a whole house system:

1. Turn off the water supply. In most cases, turning off the valve on your water pump will do this.
2. Press the water pressure release valve on the top of each chamber. This will release water pressure between the filter and the pump. If there is pressure in the filter, you’ll find it really hard to unscrew the chamber or the lid.

3. Unscrew either the water filter housing or it’s lid. If the filter is mounted by its lid, you will need to unscrew the housing. If the filter is mounted by the housing, you will need to unscrew the lid. Often, manufacturers supply a tool to do this. The housing can be on quite tight, so don’t be afraid to use force if you need to. The housing or chamber will still be full of water, so it will be heavy!
4. Remove the old water filter cartridge and either discard it or wash it. Tip the water out of the chamber when you do this.
5. Insert the new water filter cartridge into the housing unit/chamber. Screw the lid on or screw the chamber back into its mounting.
6. Turn on the water supply to the unit and check for leaks.
7. Run some water through all of the taps in your home to clear any air bubbles from the lines.

Messy and costly mistakes to avoid when changing a water filter

1. Not turning your water pump off if you are on tank water. Expect water to spray everywhere if you forget to do this.
2. Not releasing the water pressure. Forgetting to press the release valve on a whole house system or run the tap on an under sink system can leave you wondering why the filter chamber won’t come off.
3. Not preparing a shallow bucket or towel to capture any escaped water.
4. Underestimating the weight of the filter housing when you remove it from its mounting. It’s heavy and full of water – be prepared!
5. Not sealing the water filter properly. You need to screw it in tight to get a seal sometimes!
6. Not changing like for like or mixing up your cartridges. Water filtration occurs in stages using 2 or 3 cartridges. Different types of water filter cartridges remove different types of contaminants. The first filter next to the water inlet removes large particles like sediment. The last cartridge next to water outlet removes micro particles like bacteria. Make sure you put the same cartridge type back in the same housing unit.

7. Not flushing the new cartridge. Be sure to run some water through the new cartridge for a few minutes before using it. Otherwise you may notice a decrease in water pressure or strange tastes or odours in your water.
8. Not discarding the old cartridge properly. Some water filter cartridges can be recycled or reused, so be sure to check the manufacturer’s instructions before throwing it away. You may be able to clean it and save money on a new cartridge.
9. Not checking for leaks. Always check for leaks after changing the cartridge, both at the housing unit and at all of the faucets in your home. A small drip is normal, but a steady stream of water indicates a problem that needs to be fixed.

Conclusion

Changing your water filter cartridge is a simple task that anyone can do. But it’s important to follow these step by step instructions and do it right in order. Jumping straight in can leave you with a great big, costly mess to clean up. This step by step guide will arm you with the knowledge to take on your water filter confidently and save on plumber fees. Avoid our 9 common mistakes and you’ll be on your way to securing safe backup water in can of any emergency or natural disaster.