Pool Filter Leaking from Backwash – 5 Main Reasons and 8 Simple Steps to Fix This Problem


pool filter leaking from backwash

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A pool filter plays a crucial role in keeping your swimming pool water debris free and hygienic.

Therefore, regular maintenance of the pool filter is equally important if you want keep your swimming pool sparkling clean.

You must be amazed to know that maintaining pool filters is not that complicated.

Most of them are user-friendly and relatively easy to maintain.

Sand pool filter is one of the most popular types of the pool filters.

They have the simplest maintenance methods.

The process of backwashing is a simple yet important method for cleaning and properly maintaining pool sand filters.

As the name suggests, backwashing simply means reversing the flow of water in the pool filter.

It is performed to flush out residual dirt and debris from the sand bed.

The normal operating pressure of the device is utilized to run the backwashing operation.

All sand filters use special filter sand as a medium of filtration.

This filtration sand is filled in the filter tank.

When the impure water from the pool passes through the filter sand, all the dirt and debris are captured by the sand bed.

The resultant clear water is diverted back to the pool by using the control valve.

This filtration process continues until the entire pool water gets recirculated.

But gradually the dirt and debris stuck in the sand bed will start to obstruct the flow of your swimming pool water.

Hence the rate of clean water flowing back to the pool decreases gradually.

If this happens, the pool water no longer remains clean and becomes unsafe for swimming.

To tackle this issue, you have to perform the back-washing method of your pool filter.

In addition to this, if the PSI value of your filter is more than 8-10 lbs than its normal baseline value, your filter needs backwashing.

Also, a decrease in the clarity of the water flowing out of the filter indicates that the device needs backwashing.

Sometimes, leakage can be seen from the pool filter’s backwash.

When this happens, the following situations may arise.

Scenario 1: A dirty swimming pool

Scenario 2: Water wastage.

Although it may be insignificant at the beginning, it may gradually drain the pool.

This will increase the risk of running the pump dry.

Scenario 3: This action can even burn and damage the seals and fitting of the device.

Users may need to bear the expense of costly replacement of pool pump parts.

So, if you observe that your backwash valve or hose is leaking, fix it immediately.

A delay may make you to incur heavy repair expenses later on.

Let us now dig deeper and understand the 5 main reasons for pool filter leakage from the backwash and also understand 8 steps to fix this leakage problem asap.

5 Main Reasons for Leakage of Pool Filter from Backwash

As discussed earlier a leakage from backwash can be harmful for our health.

I have listed 5 main reasons that can cause such a leakage in the pool filter as follows.

Reason 1: Displacement of Spider Gasket

This tool is present with the multiport valve (MPV).

It makes sure that the water inside the filter flows in the prescribed path.

When the MPV is in filter mode, the spider gasket blocks the other ports of the valve.

It makes sure that the filtered water is following the intended path.

But when the spider gasket gets displaced, there is no such blockage in the MPV and water may leak through the backwash.

The reasons that may cause the spider gasket to displace are as follows.

1. The change of the filter setting without turning off the pump.

2. MPV has multiple ports and can perform various functions.

Frequent changing of MPV from one setting to another can create negative pressure in the valve and cause the gasket to displace.

3. Poor maintenance or long-term usage can also cause displacement of the spider gasket.

Reason 2: Damaged or Twisted Spider Gasket

Sometimes the spoke in the spider gasket may get damaged.

In such a case, it will not be able to perform its function properly and water may leak through the backwash.

Generally, spider gaskets may get damaged due to 3 main reasons such as:

1. Long-term use

2. Too much chlorine or improper pH of pool water

3. Debris in MPV

Also, the spider gasket is made of a flexible material.

If it gets twisted, it will allow water to pass through the backwash.

The spider gasket may get twisted due to the following two reasons.

1. Very large debris is forcefully passed through the spider gasket.

2. The spider gasket shrinks when exposed to very low temperatures.

This happens when the pool is not winterized.

In this case, if you find that spider gasket is damaged or broken completely, then you certainly need to replace it with the new one.

Click Here to Get New Spider Gasket for Your Pool Filter.

Reason 3: Loose Compression Spring

A compression spring is an important tool for your pool filter.

It seals the connection between the spider gasket and MPV tightly.

This action prevents water from leaking from the backwash valve and the other valves.

When this spring gets loose, the seal between the spider gasket and MPV also weakens.

In this case, water can leak via the backwash valve.

The main reasons that can cause the compression spring to get loose are as follows.

1. Corrosion

2. Damage due to long-term usage

3. Frequent changes in MPV settings

Reason 4: Damaged Multiport Valve (MPV)

The multiple ports of MPV are responsible for carrying out different functions in the pool filter.

In a typical pool sand filter, Multiport Valve or MPV has three ports namely such as the pump port, return port and waste port.

The pump port is responsible for receiving impure water from the pool.

The return port is used to direct the filtered water back to the pool while the waste port is used during the backwashing operation.

When the MPV cracks, there is no regulation in the flow of water.

Water will leak from the backwash in such a situation.

The reasons that can cause the MPV to crack are improper handling and Wear and tear due to long-term usage.

If you see that MPV of your pool filter is completely damaged or broken, then in that case, you will have to remove that broken MPV and install the new one to stop the leakage of the pool filter.

Click Here to Install a New MultiPort Valve (MPV) for Your Pool Filter.

Reason 5: Presence of Debris around Spider Gasket

The presence of a large amount of sand and debris around the spider gasket weakens its sealing capacity.

In such cases, water will leak through the backwash when the MPV is operating.

The reasons that can cause such debris accumulation are as follows.

1. Lack of MPV maintenance

2. Presence of large solid debris and sand in the pool water.

To understand all these reasons in more detail, I highly recommend watching you the following video of Steve, who is the expert in swimming pool maintenance.

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8 Easy Steps to Fix a Pool Filter Leakage from Backwash

Fixing a pool filter leakage from the backwash is not that hard to fix if you know the right steps to solve the problem.

You can easily repair it by following the below-mentioned 8 simple steps.

Step 1: First turn off the pool pump and thus, you can release the pressure from the filter.

Step 2: Slowly remove the MCV screws and then remove the MCV valve.

Step 3: Now, remove the spider gasket and inspect it properly for any visible damage.

Step 4: If you find the spider gasket displaced from its place, then re-assign r re-install it to its proper place.

If it is broken or damaged then you need to replace it with the new spider gasket.

Again, if it is neither broken nor displaced then you just have to clean it properly and then reinstall it carefully.

Step 5: After this, you will need to examine the compression spring.

If you find any damage, it is advisable to replace it with the new compression spring.

Step 6: Then, I recommend cleaning the housing of the MCV.

The presence of dirt and debris in MCV is one of the major reasons that cause the leak from the backwash.

You need to gently clean both the top and bottom sides.

But while doing so you must not exert too much force.

If you apply too much pressure, then it may damage the MCV housing in the process.

So, be careful while cleaning it.

Step 7: Once the MCV housing is cleaned thoroughly, you need to replace the spider gasket in its position.

You can try using vinyl glue adhesive on the spider gasket to prevent it from further displacement.

Step 8: Now re-assemble the MCV.

Close the filter pressure release valve.

Before starting the device again check the connection of each of the valves of the MCV.

Make sure there is no leakage from the backwash.

If you have applied the vinyl glue on the spider gasket, you have to wait for about 24 hours before starting the pump again.

And that’s it.

If you follow these 8 steps religiously, then I am sure you will be able to fix the leakage of your pool filter from its backwash.







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