Does your home have a whole house water filter? Need help on how to change it? I know I did so I ended up writing this instructable so I wouldn't forget the steps involved!

Step 1: Be Prepared! Here Is What You Need...

Print out this checklist and check it off as you go through the items. This will save you time and prevent epic fails!

☐ Do you know how to shut off water to your house?

Look for where your water meter is at the curb and verify you have a water shut off key or wrench. If you've never turned your water off before this is a good time to practice doing it to verify your valve can be shut off and re-opened. If you can't turn it off call your water utility for help. They may need to switch out valves. If you are in an apartment or condo check with the manager or home owner's association to see where your unit's shut off valves are located.

☐ Verify all your water using appliances are turned off. This includes items like the dishwasher, clothes washer, ice cube maker, sprinklers, etc. Tell folks to use the bathroom now before you shut off the water. Make sure you flush the line after changing the water filter to avoid problems with sediment, rust or backflow.

☐ Do you have the correct replacement filter on hand? Take a look at your water filter housing for a model number you can look up. Most whole house sediment filters are standardized around the 10 inch tall by 4.5 inch diameter filter. Larger homes may have the larger 20 inch tall by 4.5 inch diameter filters. If your filter system is under the sink and is just for one faucet then this is the wrong instructable. We are talking about whole house water filters affectionately called Big Blue. There are various brands 3M AquaPure, Aquaboon, Aquasana, Culligan, Dupont, GE, Kenmore, Paragon, Pentek, Whirlpool, etc. The filters are pretty standard and interchangeable between brands. Most are made from polypropylene plastic and just filter out sediment from you water supply. Some filters are string wound water filters, others are pleated cotton and some even have charcoal fiber (usually coconut husk) to improve taste. The standard is 5 micron filtration. Going with a smaller micron size usually means diminished water flow in exchange for finer particle filtration. These filters trap physical debris in your water supply that you will see embedded on the outside of filter and at the bottom of the cannister. Whole house water filters do not filter out lead, fluoride or bacteria.

☐ Do you have the Filter Wrench? This is the big circular wrench that goes over the filter housing. It is pretty useless which is why you are probably reading this article. It is important to have on hand, but if you don't you can use a strap wrench which works much better.

☐ Do you have a strap wrench? You can skip this step if you don't, but if you have problems getting your filter cannister open you should buy one instead of breaking your plastic filter wrench (which is what most people end up doing). You may already have a rubber strap wrench which you can use, but if you don't have one I recommend the Lisle 60200 Heavy Duty Strap Filter Wrench. It requires a 1/2" socket drive handle to turn but it was the only thing that I could use to get my Big Blue filter cannister open.

☐ A replacement O-Ring for your big blue filter. This is probably the biggest roadblock and source of leakage! Having replacement O-Rings on hand is really a requirement unless you have a valve bypass which lets you turn your home's water back on without having the water going through a leaking whole house filter. Finding the right replacement O-Ring is a PAIN and is usually way overpriced. Start with your whole house filter's brand name and model number. If you don't have it you can order a generic one or you can measure your existing one. I ended up running into problems finding one for my Paragon HD3000 which uses a 6” O Ring Buna-N and had to recondition and re-use it (explained later).

☐ Food Grade Silicon Grease. This is used to lubricate the threads on your whole house filter canister. You need to use an approved food grade lubricant since you can end up getting your drinking water contaminated with it. I used a tube of Super Lube Silicone Lubricating Grease. The key is to look for the NSF rating of H1. This means that the FDA recognizes NSF (a company that certifies products) of using chemicals that are okay with incidental contact with food (in our case water). Do not overpay for this. You don't need a lot either.

☐ Plumber's Tape also called Teflon Tape or more specifically PTFE Thread Seal Tape. This is that thin white slippery plastic tape you use on plumbing fixtures to get a good seal. This was the key to solving my Whole House Water Filter's leaking problem I had when I went to reassemble my filter. Don't pay more than a few bucks for it, but do get one with a cover to keep it clean and from unravelling.

☐ A big bucket to put under your whole house filter to handle spilled water and leaks. I used our mop bucket but if it fits I would recommend the standard 5 gallon plastic paint bucket available at any Home Improvement store.

☐ Some rags for wiping things down and cleaning up once you are done. Make sure they are clean and low lint (white cotton towels are best) since you'll be using them inside the filter housing.

Got everything? Okay let's get started!

Step 2: Turning Off the Water and Depressurizing the System

Ideally you would shut off the water to your entire house, but for those of you foolish enough to proceed please do so with caution! The last thing you want is a full blast of water coming in with no method for shutting it off.

Take a good look at your whole house water filter setup and understand which way the water is flowing.

Most setups have the main water line pass through the whole house sediment filter and then branch out to other water filters or soft water conditioners before splitting out into the cold water line for the house (sinks, toilets, dishwashers, fridges, washer machines, etc) and the hot water line which gets fed into your water heater (either a big water tank or an tankless water heater system).

A good tip from Fichtner is to fill up a sink or bucket full of water before you turn off your water. This way you have water available for rinsing or washing up.

Once you've turned off the water to your house go and open up a faucet sink valve or bathtub to let the water pressure release. Ideally do this at the faucet with the lowest elevation in your home to help drain out most of the pressure in the line. Why do this? If you open the 2nd floor bathroom faucet and are changing the water filter in your basement you'll have 2 floors of water still in the line when you open the filter in your basement - hence the bucket).

I usually leave the faucet open to help flush any debris water out the system when you go to turn the water back on, but do what works best for your setup.

Step 3: Whole House Water Filter Bypass

If you are lucky you'll have 3 valves which let you isolate the water filter setup. The valves are usually usually simple handles that turn 90 degrees. When the handle is flush with the pipe water is allowed to flow. When the handle is 90 degrees from the pipe it is shut off. Some systems use flower stem handles in which case righty tighty is closed and lefty loosey is open.

The first handle to your water filter you'll want to turn off. This prevents the water intake from reaching your filter.

The second handle after your water filter you'll want to turn off. This prevents a back flow of water in the line from coming back to you when you open the filter housing.

The third handle is the bypass handle that should have been off (ie it was forcing the water to go through your water filter). You'll now want to open this handle. This means that if your water line is still on (or not completely shut off) it will continue on by passing the water filter. This setup is what you would do if you end up with a leaky whole house water filter that you need to bypass while you make repairs but still providing unfiltered water to the rest of the house.

Step 4: Opening the Big Blue Filter Cannister

Most people complain they can't open their filter's housing and complain about the plastic filter wrench.

In most cases this is either because they over tightened the filter or the system is still pressurized.

Better whole house filter systems have a red button on top that lets you release the water pressure in the line to make it easier to open the housing. If you have this red button and your water is shut off go ahead and press it. If you hear pressure releasing you have just saved yourself a lot of arm wrestling with the wrench.

Some filter systems even have a built in bypass. I'm not familiar with their setup, but hopefully it is straight forward setup.

With the bucket under your whole house filter and your wrench around the filter go ahead and turn counter clockwise (once you figure it out mark an arrow on your housing so you won't have to use your brain). If you are slow minded like me you'll grab a jar and unthread the lid by holding the lid and turning the jar to visually compare which way you should be turning.

If it starts to move proceed SLOWLY. A lot of water is likely to start coming out and you don't want to completely remove the filter housing until you verify the water lets up. If you completely remove the housing and your water is still turned on you are going to have one heck of a time trying to get it back on or rushing out to shut off your main water line.

If your filter housing is NOT moving proceed carefully. You don't want to put too much pressure on the plastic filter wrench. It will break! Some folks put two filter wrenches on. Others put a plastic pipe over the end of the wrench to create a longer bar with which will give them better leverage. You'll want to be careful you don't tear the bracket mounting from the wall, or worse pull the pipe from the wall.

If you can't get the filter housing off you should go and use a strap wrench. The rubber ones are okay, but the safety belt fabric strap with metal attachment for hooking a socket wrench bar is the tool you want (Lisle 60200 or maybe the GearWrench Oil Filter Strap - just make sure the strap is wider than the outside of your filter cannister). You'll want to put the strap all the way around the center of the filter housing and then run the excess strap through the metal buckle and turn the buckle so that it grips the fabric instead of bare metal on the housing. Most canisters have natural groove lines you'll want to lean it up against. You'll then insert your socket wrench into the strap bracket and then turn clockwise (or counter counter clockwise). Take the time to think it through - basically two gear motions to give you the final lefty loosey motion to UNTHREAD your canister. Turn the filter canister the wrong direction and you'll crack the replaceable housing or worse the threaded top in which case you'll need a plumber to fix this mistake.

Fichtner gave the tip of using a rubber mallet and gently tapping the plastic wrench to help loosen the filter housing. If you have hard water it is possible that the calcium deposits have built up where the thread pattern is. Proceed with caution, and be sure to clean them out. Vinegar is an acid that will help to remove hard water build up. You can use a toothbrush and gently apply vinegar to the mineral build up areas if needed.

Once the canister housing starts moving use your hands underneath to verify you are turning it level. This will prevent any stripping of the threads or having the cannister falling to the ground. You should get a surge of water coming out and then the water leak should go to a trickle as your remove the housing.

Step 5: Inspect the Old Filter and Clean Out the Filter Housing

Congrats! You are 1/2 way there. Sorry this is so verbose, but I wanted to make sure all the gotchas are documented for those that run into problems like I did.

Pour the filter housing water into the bucket below and look for any big sediment pieces that might indicate you are getting contaminated water from a broken water line. The water should smell fine, if it doesn't it might be a problem with your water source (fracking near water wells) or a lack of chlorination for water utility lines. Investigate any serious issues.

Pull out the disposable filter. These are supposed to be replaced every 6 months, but in my case it had been almost 2 years! The outside of the filter is where the water comes in so all the debris should be on this side of the filter. Take a look inside the center filter ring to see how it looks (this is the filtered water that proceeds out to your faucet. If you see small black flecks it may be from a charcoal filter. If you see rusty metal flakes it probably means you have steel pipes that are starting to deteriorate. A small amount of sand is not unusual. A lot of sand, pebbles or concrete pieces is not normal.

Take a look at the bottom of the filter housing for more debris. Rinse it out and use a clean rag to wipe down the insides and outsides of the canister.

Clean out the threads of the canister as well as the threads of the cannister holder bracketed to the wall. You may find chunks of debris lodged in here from opening the canister. It is important to clean this out well. Use a Q-Tip or tooth brush and then wipe it clean with your rag.

Step 6: Inspect and Replace the O-Ring

Your filter canister has a black o ring that is a food grade safe gasket to help prevent leaks. This O-Ring is the seal between the canister and filter bracket and is critical for preventing leaks. Most people think they just need to tighten harder rather than realizing they need a new O-ring.

Carefully pry the O-Ring from the cannister. Take a look for any flattened parts. be careful to not stretch the ring because if you end up re-using it, it might not fit again.

Clean out the O-Ring track with a q-tip. It might feel tacky from the silicone grease used on it last time. Try to get it clean, but do not use any detergents or solvents to do this.

Be sure the replacement O-ring fits nicely into the track. You'll want to go ahead and put some silicone grease on your fingers and rub a light coating onto the ring.

Check the diameter of the old ring with the new one. The new one should be the same size or slightly thicker in diameter.

If you are reusing the old ring use your rag to clean off the old grease. If you see brown gunk coming off the old ring take the time to clean it all off without stretching out the O-ring. As they get older they get brittle.

Don't see an O-ring gasket on your cannister? You should also look under the bracket housing and make sure there it isn't stuck up there. Some folks have reported that their setup has a second set of O-rings up there as well (mine did not).

Take the time to make sure you are ordering the right kind of O-Ring replacements. They should be Nitrile NSF 61 O-Rings that are also called Buna-N O-rings. These are certified safe for water that may come into contact with them (ANSI standard 61).

The key measurements to know is the inner and outer ring diameter (use a ruler to measure) and the thickness (use a pair of calipers if possible). When bought in bulk they cost pennies apiece, but it amazes me that folks pay several dollars for a new one. Take your time shopping around. Better sellers will often include them with your filter replacement and some will even throw in the food grade silicon grease too.

Step 7: Putting Plumber's Tape Around the Threads of the Filter Canister

Almost everyone skips this step, so you are welcome to skip it too, unless you are running into a leaking problem like I was.

Take the Plumber's PTFE Teflon Thread Seal Tape and wrap it several times around the threads. You'll want to get good coverage without over doing it.

The trick is to make sure your thread this on correctly the first time, otherwise you'll need to remove it and start all over again.

I find that it works best just using my two hands and holding it super level as I slowly turn the canister CLOCKWISE (righty tighty) works best.

Before you do this though make sure you've got the new filter in the casing!

Step 8: Putting the Replacement Filter In

Pretty straight forward. Some folks presoak their filter in a bowl of clean water. This is important if your filter has charcoal. In most cases you don't need to do this step and it does make the filter much heavier!

Put the filter into the housing so that it is perfectly centered. If it is off center or you tilt it while you thread it, you are likely to damage the top of the filter as it smashing into the brackets designed to help guide the canister housing back on.

Take the time to look at your filter in the canister and at the threads you are screwing it onto.

You do NOT need the filter or strap wrench. The usual protocol is to hand tighten only. It will go on easy enough and once the water is in it will be difficult to unthread until the system is depressurized.

That said, too loose and you'll leak. Some folks cheat and do a little monkey tight (not gorilla tight) with the filter wrench, but this step is done because they didn't install a new O-ring, use silicone grease and/or PTFE tape. You'll know if you are over tightening when you go to do the filter change next time and end up having to use the strap wrench to get it opened!

Step 9: SLOWLY Pressurize the Water System

Don't just go and turn the water system back on to full pressure and not expect a leak!

Some folks turn on the water, only to find out the canister fell off and water is spraying everywhere!

I recommend slowly turning the water to 1/4 open and listening to the pipes. If you have someone else turn on the water while you watch you can catch any problems quickly. Leaks will either appear as a steady stream of drops down the side or a huge geyser of spray at the connection.

If you have bypass valves at the water filter go ahead and turn off the bypass and do a slow 1/4 open on the water into the filter, and then a 1/4 open on the water out. You should hear water rushing through the system, and if your faucet or hose is open you should hear it gurgle as it pushes out the air followed by the water.

This is a good time to check for rust and debris getting flushed out in the lines. If you see this you should let the water run until it goes clean before proceeding. Once the water is running clear you should go up to the highest water outlet in your house (usually an upstairs shower) and turn it on to purge any air out of the water lines.

If there is any sign of leakage shut everything down. If it looks okay go ahead and go to 1/2 water pressure and then full water pressure.

Step 10: Clean Up and Final Tips

Take the time to clean everything up. Dump out the water out of the bucket, but if possible leave the bucket under the water filter for the next filter change, or in the case you have any leaks.

Take the time to put a post it note on when the filter was changed and go ahead and set a calendar reminder on your phone for 6 months out (or longer if your old filter looked in good shape) to do the next filter change.

If you don't have a water leak detector installed this is a good time to get one. I have the Gentronics water detector, which allows you to set the alarm farther away from where the leak is detected. Honeywell also makes one. They cost less than $15 and can save you thousands in repair bills. They use a 9 volt battery and only use the battery power when water completes the circuit - making a loud buzz for you to go and turn off the water.

If you already have a water detector now is a good time to wet your finger and test it to make sure it is still working.

Hopefully this instructable was helpful to you! We are lucky to live in a country with clean water. Please pray/vote/donate to help those without access to clean water.

If you have any tips please add them to the comments below for others to benefit. If you are still looking for answers check You Tube or call a plumber.