Struggling to open the filter housing or unscrew the cartridge on your whole house water filter? This is a common problem, and thankfully, it’s easy to fix.
If you’re struggling with a stuck filter cartridge or filter housing that won’t budge, you’ll learn exactly what to do in this guide.
Table of Contents
⚠️ Common Causes of a Stuck Filter Canister
A stuck water filter is most commonly caused by one of the following:
- A buildup of pressure inside the system
- Hard deposits inside the filters
- Cold temperatures causing the plastic to shrink
- Broken or damaged o-rings
- Overtightening of the canisters
🔧 How to Fix a Stuck Filter Canister
Here are a few ideas on how to unstick a stuck cartridge or tight filter housing, ranked from best to worst:
1. Depressurize the Filter
It might sound like a silly suggestion, but if you’re new to owning a whole house water filter, you may have forgotten to depressurize the filter before opening the filter housing.
If you don’t release pressure before attempting filter maintenance, you’re likely to struggle to open the filter housing – and you’ll probably end up getting water all over you, too.
Here’s how to depressurize a whole house filtration system, making it easy to release stuck filter housing:
- Turn the system’s bypass valve to divert water away from the filters. If you haven’t installed a bypass valve, turn off the main water supply and open your home’s faucets to release trapped air from your pipes.
- Find the pressure release button on the top of the water filter housing (if there is one). Press the button until you can’t hear water and air leaving the system
Water pressure acts as a sucking force, making it incredibly difficult to remove a stuck filter canister. You should find it much easier to unscrew a filter once you’ve depressurized the filter system.
Related: Low Water Pressure After Installing Water Filter Troubleshooting Guide
2. Use the Filter Wrench
If you’ve depressurized your system but you still can’t get a good grip on the offending filter canister with your hands, try using your filter wrench.
Many whole house water filters come with their own specially-designed filter wrenches, which have a dedicated purpose: unscrewing a water filter cartridge from the housing.
It’s common for whole house filter wrenches to be made from plastic so that you don’t damage the filter cartridge by applying too much force. A plastic wrench should do the trick, unless you’re dealing with a particularly stubborn cartridge.
If one wrench isn’t enough, try using two wrenches. Just place the two wrenches around the filter cartridge – one on the top and one on the bottom – then twist them both at the same time.
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3. Or Use a Dishtowel (Or Another Helpful Item)
Not all whole house filter systems come with an included wrench. Or, admittedly, you might have just lost it.
Consider all the items you’d use to try and open a glass jar with a stubborn lid. A rubber glove, a dishtowel, or another item that potentially gives you a better grip on the filter cartridge is worth a try. If your hands aren’t working, a dishtowel can give you more leverage.
Place the helpful item between your hand and the filter cartridge, then firmly twist the cartridge with (hopefully) a bit of extra grip.
4. Try With a Metal Wrench
Now, most manufacturers strongly advise against using a standard metal wrench to unscrew a stuck filter canister, because of the risk of damage to the system.
It is possible to get your hands on a metal filter housing wrench nowadays, though – so if you’re really struggling with stuck water filter housing, it’s worth a try.
Metal filter wrenches are available online and at most local hardware stores. Make sure you’re careful not to apply a lot of force when using a metal filter wrench – they’re much more capable than plastic wrenches.
5. Tap the Water Filter
It might sound simple, but tapping a water filter is sometimes all it takes to unstick it from the filter housing.
When contaminated water flows through a whole house water filter, the minerals and sediment from the water end up collecting around the outsides of the filter, making it more difficult to loosen the housing.
Try lightly tapping the outside of the filter housing, near the rim, with a rubber mallet or your hand. This should dislodge the sediment, hopefully making it easy to unscrew the cartridge.
6. Turn the Filter the Other Way
It might sound counterintuitive to turn the filter in the opposite direction to the direction it needs to go in, but it’s part of an overall method that might just free the filter.
The correct technique for unscrewing a tight filter is to actually turn it the other way first. Slowly turning the filter case in the opposite direction will break down deposits on the rim of a filter stuck in the housing. While you’re doing this, use your hand to push the filter cartridge up from the bottom.
This isn’t guaranteed to work, but if your filter does have deposits at the connection point that are preventing it from being twisted the right way, it might help to twist it the wrong way first.
7. Apply Heat
If you’ve exhausted all the options above, and you still can’t untwist a filter stuck in the housing, it’s time to bring out the heat.
When plastic is heated, it expands. On the other end, when plastic cools, it contracts. This is why it’s often more difficult to replace an old filter with a new filter in the winter, when your water line is much colder than normal.
Get your blow dryer out and try using it on your filter housing. Not only will the heat from the blow dryer expand the plastic; it should also loosen water deposits that could be sticking the filters in place.
Aim the blow dryer at the jammed section of the housing. When the housing has warmed up, stop applying heat and use your hand or a rubber mallet to tap the filter out of the housing.
If you don’t have a blow dryer to hand, use a hot water-soaked warm towel for the same effect. Just press the towel against the filter housing to warm it up. Don’t add too much heat, as this could cause the plastic to melt and change shape.
8. Use a Rubber Strap Wrench
A rubber strap wrench performs the role of a wrench, but uses a rubber strap instead of traditional plastic or metal.
Rubber strap wrenches are useful for loosening cylindrical-shaped objects, so it’s worth trying this method if you still can’t break the filter free from the housing.
Simply wrap the strap around the canister and follow the same directions as for the other wrench types on this list. For some torque, attach a half-inch socket wrench. If you don’t have enough support, try attaching a pipe to the socket wrench.
9. Apply WD-40
Our very last-resort option for unsticking a trapped canister is to drench the top of the housing with WD-40.
This is pretty much guaranteed to work, but we recommend trying everything else before settling on this option, because WD-40 can damage the o-ring. Make sure you have a few replacements if you end up using WD-40 to loosen the canister.
🪛 How to Remove a Stuck Filter Cartridge From Canister
Maybe you’re not dealing with stuck filter housing; you’re dealing with a filter that won’t come out of the canister.
Many whole house filtration systems have water filters that slide in and out of canisters. When you need to replace the cartridge, you simply remove the old filter and slide a new one in its place.
The problem comes when the filter is stuck inside the canister. The tricks above won’t help in this case, because even if you easily remove the canister from the filter housing, it won’t help you to get the filter out of the canister.
If you can’t remove the cartridge with your fingers, try using these two methods:
1. Use Needle-Nose Pliers
Needle-nose pliers can help you to get a good grip on your water filter, making it easier to pull it out.
This is a good solution if you can’t get your fingers into the canister, or you can’t get enough purchase to pull the filter out.
Simply grab hold of a part of the cartridge with your pliers and twist it to loosen hard deposits, then carefully pull the cartridge out.
2. Apply Heat
If your cartridge is stuck fast, even using pliers might not work in the first instance.
In this case, you’ll need to bring out the heat again. Use a blow dryer to warm up the entire canister. When the canister is warm, but not too hot, tap it on the floor to loosen the stuck cartridge, then use a pair of pliers to remove it.
🧰 How to Prevent a Stuck Whole House Water Filter
Many of the methods in this list are time-consuming, and some come at an additional cost. If you want to save yourself the hassle of freeing a stuck filtration system in the future, here’s what to do:
Replace the Cartridges on Time
One of the easiest ways to avoid stuck cartridges is to make sure you’re replacing them on time.
The longer a cartridge is used, the more sediment builds up on the inside. These deposits become harder and thicker over time, eventually making it near-impossible to untwist the canister and remove the cartridge.
Most cartridges for a whole-house system last for 6-12 months, although your water usage and water quality can affect this. Follow the guidance in the user manual for replacing the cartridges. They’ll be much easier to dislodge within their recommended service period.
Grease and Replace the O-Rings
Your filtration system’s o-rings won’t last forever, and a cracked, broken, or dry o-ring makes it difficult to remove the canister. Make sure you grease the system’s o-rings regularly to prevent an impossible seal from forming. This means you won’t have to apply as much pressure when it’s time to change the filters.
Don’t Overtighten the Canister
You obviously need to make sure the canister is tight enough to prevent leaks – but no need to tighten the canister so much that you can’t unscrew it when it comes to maintenance. Follow the directions noted in your user manual to tighten the canister. In most cases, you should hand-tighten the canister or use a plastic wrench.
Remove Old O-Rings from the Canister
Most water filters come with an o-ring that helps them to sit properly inside the unit. It’s easy to forget to remove the o-ring when you’re replacing a filtering cartridge.
If o-rings build up inside the unit, you’ll struggle to push the canisters into the housing properly, and you’ll probably end up overtightening as a result. Check inside the housing to make sure there’s nothing leftover before putting everything back in its place.
Keep the Unit in a Warm Location
If you install the filtration system in a location that often gets cold in the winter, like your garage or your basement, you’re at more risk of having issues with stuck filters.
Cold weather causes the plastic in your unit to shrink, making it difficult to unscrew the canisters. Avoid this issue by installing the unit in a warm location that has access to heating in the winter.