How to Change a Whole-House Water Filter

One of the questions I always get asked is, “Do you know how to change whole-house water filters?” My first response is usually “Who are you, and how did you get into my house?” and secondly, “Of course I do, I’m the water guy, bud.”

Like most people, when you moved into your house, you probably noticed that your whole-house water supply tasted like puddle water. Nobody wants to drink puddle water—it’s gross. That’s why you went out and spent like $2,000 on a whole-house water filtration system, right?

You probably felt like the champion of reverse osmosis for a while there. The neighbors couldn’t stop commenting on your crystal-clear water, and you were the talk of the town.

Yet, you may have started to notice that the kitchen sink is producing yellow or brown water, and that familiar puddle water taste has returned. The neighbors have stopped coming over for a drink, and you caught them whispering about your nasty water behind your back at neighborhood block parties. 

Not good.

Now you’re wondering if that whole-house water system was worth it?

To do their job correctly, whole-house water filters need to be changed when they reach the end of the filter lifespan.

Today, I will lead you through a step-by-step guide on how to switch out whole-house water filters, save you mucho bucks, and restore your title of the czar of carbon filters.

Before I help you learn how to switch out your whole-house water filter, let’s have a look at what you’ll need to ensure this job is a success.

Supplies

That’s it. No other tools are needed. Simple, right?

You might not know the difference between a whole-house sediment filter or a carbon one, but don’t worry, this job is not as hard as a filter-system specialist would have you believe. I’m going to save you some money and leave you feeling like a DIY superstar when we are done with this minor filtration system project.

As always, you can find everything you need for this job at your local building supply shop, or you can purchase online from Amazon. And no, you can’t borrow my Prime membership.

Alright, let’s get your water looking and tasting like it came from the baths of Poseidon himself.

Method

Step 1: Turn off the main water supply

The first thing you will want to do is safely secure your safety goggles. Safety first. 

Now you can turn off the cold water supply going into your filter system. Look for the inlet handle (usually a red ball valve) and give it a right turn, 90 degrees. You should hear the water flow stop. If you can’t find the shutoff valve, pick up a phone and call a friend to come over and do this for you. 

You shouldn’t be near water pipes. 

If your friend comes over and they can’t find the shutoff valve, my bad, you probably don’t have one. You will have to turn off the breaker to your water pump to shut off the water supply flow.

Step 2: Open up your faucets

Head to your kitchen sink and crank open both the cold and warm water faucets to release any built-up water pressure within the lines. When the water supply slows down and comes to a stop, you’re clear to continue to step three.

Step 3: Find the next water shutoff valve

Follow the water supply line coming out of the filter head until you come across the next shutoff valve. It could be anywhere, so keep going until you come across it. Once you have located it, do a little dance, give it a 90-degree turn, and slowly turn it off. It will help prevent any remaining water in the house from draining back into the housing unit, keeping your feet and basement dry as a bone when you make the switch.

Step 4: Locate the red pressure-relief button

Take a look at the top of your housing unit and seek out the pressure release button. It’s usually red and has “release” written on it or around it. Give it a push. Did anything blow up? Good, we can continue. This button will relieve pressure within the housing unit, making it easier to remove the housing when you are ready to switch the water filters.

Step 5: Loosen the housing unit

Remember that big plastic wrench I told you to pick up earlier? Take that and place it up and around the housing unit. Now turn the housing wrench to the left. 

Is it not coming loose? Try your other left. 

Yeah, there you go.

Step 6: Grab the empty bucket

When you have finally loosened the housing unit, grab that empty bucket and place it underneath where you are working. This will catch any remaining water within the housing unit and keep your partner happy because you didn’t ruin the floor again.

Step 7: Remove the housing unit

If your bucket is in place, you can begin removing the water housing unit. Do it gently, or you’re going to experience a pretty good drenching. The water should be slowly trickling from the sides as you do this, so don’t panic if you see any.

As you turn the water filter unit left (your other left), place a hand underneath the housing, as it will be full of water and the old filter. That way, it won’t drop into the bucket, creating a tidal wave aimed directly at you.

Step 8: Remove the old filter cartridge

At this point, you can remove the old filter cartridge from the water housing unit. 

See how brown it is? That’s nasty. 

You should change these house water filters annually to ensure that you and your family never have to drink puddle water again. Set a reminder, so you don’t forget again.

Step 9: Pour out the water

Once you’ve removed the old water filter cartridge, you can go ahead and get rid of any remaining water within the unit itself. You can pour it down the drain or even keep it in a glass jar to remind you how gross your water will be if you forget to change your water filter cartridge each year. The choice is yours. 

I’d pick the jar, but I’m a visual learner. You do you.

Step 10: Wash out the housing

Remember when I asked you to fill another bucket with clean soapy water? That wasn’t because I wanted you to blow a ton of bubbles. I mean, you can, but the reason was so you could take that soapy water and use it to clean out the unit thoroughly. Go ahead and put some elbow grease into it, leaving no debris inside.

Step 11: Seek out the O-ring

In between the top of the housing unit and the female end to connect it to, there should be a black O-ring. Most of the time, these O-rings will be sitting in between where you would screw the housing unit on. If you can’t see it, the O-ring is likely caught up inside where you would attach the housing. Reach up inside to locate it. 

This O-ring creates a waterproof seal, so please ensure that you have it in place before you screw the housing back on. 

Step 12: Install the new replacement filter

We are almost there! It’s time to put the new water filter replacement cartridge into the filter housing, but before you do, make sure you remove the plastic wrap covering the new filter cartridge. 

If you don’t, your water stays tasting like puddles but now with a hint of plastic. 

You don’t want that. 

Once you’ve removed the plastic, place the new filter cartridge back into the housing unit.

Step 13: Use clean silicone grease to seal

Take the food-grade plumber’s silicone grease (again, not for eating) and squeeze a bit of it to apply to the O-ring. You’re going to use the food-grade plumber’s silicone grease because it allows the O-ring to sit naturally and creates an even better waterproof seal. 

Remember, all it takes is a very thin layer of clean silicone grease—you’re not trying to body massage this O-ring, so go easy.

Step 14: Reattach the housing

Now that you have your water filter cartridge in place and your O-ring is nicely greased go ahead and spin the filter housing hand-tight and to the right (your other right) until it fits snugly into the top of the housing unit. 

Once you have got it as completely shut as you can using your hands, get that filter housing wrench again and place it up and around the filter housing. Give the plastic wrench another slight turn, usually about an eighth of an inch, and lock it in place.

Step 15: Open up the water inlet valve

Head back to where you started and find that valve for the cold water supply. 

You can now turn it on to release the water flow, but please, do it slowly. 

Open it only halfway and let the housing slowly fill up again. This way, you can check for leaks and ensure that the filter stays in place.

Step 16: Open up the outlet valve

Once you have the inlet valve fully opened up, you can move to the outlet valve you shut off before we began and open that up. This will send the water supply back into your home.

Step 17: Open up your water faucets

You can now head over to one of your many sinks again and turn on both the cold and warm water taps to test pressure and make sure that the filtered water moves freely within your home. 

At first, the flow rate will come out in spurts and will seem like the water taps are choking on the clean water you’re filtering. 

That’s because they forgot how good clean water is, you bad homeowner, you. 

I’m kidding—it’s just because the water pressure is building up again, and the filter is running for the first time. 

Let the water run until you get a nice stream and any milkiness or gray color has dissipated. At this point, your water pressure should be good and your flow rate restored.

And you’re done!

So that’s it! You changed a whole-house filter, all by yourself. Let’s see those water filtration specialists laugh at you now.

By learning how to change a whole-house filter, you’ve saved a bunch of money. Most filters and changes can cost you anywhere from $100 to $300 each year! With savings like that, you could send me $50 annually to thank me and still have money left over to do as you please.

Look, I told you a filter change wouldn’t be that hard. I like being right! What can I say?

If you’ve followed along, I’ve helped you collect the supplies you needed to get the job done right. 

I covered how to go about shutting off and engaging the whole-house water supply. 

I showed you how to successfully remove the housing unit and safely put it back on while creating a waterproof seal. 

Heck, I even gave you pointers so you wouldn’t drop the housing and create a basement tsunami.

I covered the whole filter change process in 17 steps!

As far as I’m concerned, this has been a splashing success without the splashing. 

It seems like there’s only one thing left to do. Go outside, turn on every sprinkler you have, and run through those sprinklers like the legend you are. That will show those neighbors that were whispering behind your back. 

The czar of carbon filters has returned!