Richard Arconti 
If you’ve noticed your whole house water filter leaking recently, you’re probably wondering what is causing the leak. There are actually a number of possibilities. It may be a bad O-ring, a damaged fitting, or just the result of normal use over time. Whatever the problem is, you’ll need to track it down before you can fix it. So, in this article, we will explain how to identify the cause of a leak, fix the leak, and some steps you can take to prevent future leaks.
Why Is My Whole House Water Filter Leaking?
There are a number of possible causes for a leaking whole house water filter, and here are a few of the possible reasons.
- The threads on the system have been over-tightened or under-tightened.
- The system is not well designed or has defects.
- The system is old, and some parts need replacement, or possibly the whole system.
- The filter cartridges are clogged and need replacement.
- The O-rings or other connections are damaged or cracked.
- The system may not be the proper size for your home’s water pressure.
How To Stop A Leak In Your Whole Home Water Filter
Fear not! Now that we know common reasons why your whole home filter is leaking, we can look at some ways to diagnose and fix it.
The first step is pinpointing the exact location of the leak. This can be tricky if there is a lot of water flowing from the system, but knowing where to start will save a lot of angst. The good news is if your whole house water filter is leaking, there is a good chance it’s a simple fix with the filter canister, housing, or fittings.
Here are the steps to identify and solve a whole house water filter leak issue:
Step 1: Pinpoint The Leak Location
Before taking further action, we need to identify exactly where the leak is coming from. Knowing the location of the issue is going to save us time troubleshooting it in the steps to come. Do this prior to turning off the main water supply.
If your whole house water filter is leaking from the top, see if it is because of a crack in the housing or within the connection threads. A cracked or damaged component will likely mean replacing the specific part or entire system. If it is leaking at fittings, there is probably an O-ring or an internal component that can be addressed.
A filter leaking from the top is typically caused by damaged threads, a broken O-ring, or a crack in the filter housing canister itself.
Step 2: Turn Off The Water Supply
It is critical to turn off the main water supply before starting the task. Since a whole house filter is installed at the main point of entry, the valve should be in close proximity to the system. If you are unsure where the valve is located, this is a good time to find out.
Now that the main water supply is off, we need to drain any remaining water from the plumbing. To do this, open a faucet until all the water flows out. It is best to use a faucet on the lowest level of the home to ensure all the air and water are completely removed.
Finally, if you have a pressure release button located on top of your filter canister, press it. This will release any residual pressure occurring within the housing.
Step 3: Detach The Filter Canister
Since most leaks start from within the filter canister, you are going to need to remove it. To do this, follow these steps.
- Switch on any bypass or shut-off valves for your unit to prevent any accidents or water damage. The bypass valve will also allow the water supply to your home to continue as you work on the filter system.
- For this step, people who have a big blue canister-style filter should use a filter housing wrench to turn the housings. Be sure to use this wrench, it typically comes with the system.
- You will want to place a large container beneath the filter housing to collect any water.
- Using the filter wrench, turn the cartridge counterclockwise to remove it. If your filter is stuck, you may have to give the wrench a small nudge. However, if it will not come off, you can follow additional steps to resolve a stuck water filter cartridge.
Step 4: Examine The Filter Cartridge
Carefully inspect the filter cartridge and change it if necessary. Like all water treatment systems, filter cartridges require periodic replacement. If your water is especially contaminated with sediments, hard water, or TDS, the filter will need more frequent changes.
These cartridges can become clogged and do not allow water to run through them. If this is the case, water pressure will drop and it may cause cracks in the filter canister.
If the filter is restricting flow, as water enters the filter housing, pressure will build and force water to leak from the threads or connections. This makes it vital to replace your filter on time to avoid further damage.
Step 5: Check The Rubber O-Ring
Examine the O-rings for any damage and replace them as necessary. After several months of use, the silicon O-rings will need to be replaced. Each filter housing will have an O-ring located on the top of the canister to ensure a tight seal with the manifold head. Make sure the O-ring is clean and free of any cracking. Something as simple as a dirty O-ring could be the cause of your problem.
You must also make sure that the O-rings are sufficiently lubricated with food-grade silicone grease. This is necessary in order to create a good seal and prevent cracking. After you have made sure the O-rings are lubricated, check to see if they are seated correctly. If they are not seated properly, you should replace them.
Fortunately, a replacement O-ring will be available at any hardware store for less than $5. But be sure you lubricate any new O-rings as well.
Step 6: Examine The Exterior, Interior, And Threads Of The Canister
Overpressure, either inside or outside of the filter canister, can cause hairline cracks which may lead to leaks. So, look for cracks on the exterior and interior of your filter housing or canister. You may also want to submerge the canister in water to check more carefully for leaks. Another method to identify fine cracks is to use a bright flashlight to illuminate the housing.
Also, look at the threads to see if they have been damaged as a result of over-tightening. In some cases, the cartridge may have been improperly fastened which can lead to cross-threading. If the threads were compromised in this process, using plumber’s tape might save it.
At this point, it is also a good idea to clean the interior of the canister with warm soapy water. This will help with overall sanitation, but also aid in spotting any leaks.
Step 7: Reinstall the Filter and Look for Leaks
After you complete the above steps, it’s time to reinstall the filter canister. If you have not already done so, apply plumber’s tape to the filter housing threads. A little tape goes a long way, so only wrap it 4 – 6 times around the threading. Be careful not to over-tighten or under-tighten, as either of these may cause leaks.
Use the filter wrench to tighten the filter canister. Ensure the O-ring is still properly seated and lubricated as you reinstall.
Then, slowly turn your water supply on a quarter turn to let your filter run. Use this time to closely inspect the system to make sure the leak is resolved. If there is any indication of the leak persisting, turn the water supply back off. If the leak is repaired, you can turn the water supply slowing back on to let the water pressure come back to the system.
Whole House Water Filter Leaking At Fittings
If your whole house water filter is leaking from the fittings or plumbing, it is likely due to a cracked pipe or loose connection. When there is not enough Teflon tape used during installation, water can leak from the valve fittings.
- Turn off the main water supply line
- Disconnect the valve fitting
- Apply Teflon tape to the male fitting threads
- Re-connect the fitting and slowly turn on the water supply
If the fitting is still leaking after applying Teflon tape and re-tightening the connections, you may have faulty valves or plumbing. In this case, you will need to remove and replace the affected area with new components.
How To Prevent Leaks in Your Whole House Water Filter
There are some things you can do to prevent a leak, which could save you some trouble in the future. Try taking the following steps to keep your whole house water filter in good condition.
Regular Filter Replacements
Filter cartridges are meant to be replaced periodically. How often you should replace your filter cartridges will depend on both the quality of your water and the amount of water your household uses. But be sure to replace these cartridges as needed to avoid the cartridges becoming clogged and possibly damaging your filter canister.
You may be able to get a longer useful life with a reusable filter or a high-quality NSF certified filter. But, no matter what kind of filter you are using, it will need to be replaced every few months.
Utilize the Right-Sized System
If you install the wrong size system, it may not be meant for your water pressure and could become damaged or cracked. So, be sure to select the right size filter system for your house.
Clean the System Regularly
It is essential to properly maintain your filter if you want it to work well, and one way to do this is to keep it clean. This doesn’t involve a lot of work or buying expensive equipment. You just need to use NSF-certified sanitizers or a gentle, non-toxic cleaner to clean the assembly line, top, and inside the housing.
Lubricate O-Rings
Another important part of maintaining your system is to regularly lubricate the O-rings; doing this can help the O-rings last longer, thus helping to prevent system breakdowns. This is particularly important when replacing the filter cartridges.
Utilize a Water Leak Detector
This is one of the easier ways to find a water leak in your system. Using a water leak detector could help you to find the leak in your whole house water filter before it becomes serious. A serious leak can cause flood damage to your home and can require expensive repairs. So, installing a leak detector may be worth considering.
Replace Sediment Filter
If you have water with high levels of sediment, you should install a sediment filter. Sediment can clog your filters and get stuck in the O-rings around the filter canisters, which can cause the O-rings to become hard or fail to retain their shape.
