How Can I Tell If My Hot Tub Is Leaking? (Here’s How!)

By James Brockbank •  Updated: 12/28/21 •  14 min read

How can I tell if my hot tub is leaking?

If your hot tub is losing more than 2 inches of water per week, there may be a leak. If you notice water pooling at the hot tub base when the jets are on, or if you hear an unusual leaking sound from inside the spa, then a leak may be present. Due to evaporation, hot tubs can typically lose an inch of water each week.

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A great product to help slow and prevent leaks is Fix-A-Leak.

A water dye can also help you find leaks.

Many maintenance measures are required on a hot tub, including the usual chemical balance that every hot tub owner knows about. 

But if you asked me, the worst of all is experiencing a leak on a hot tub.

There’s a time I wondered, “How can I tell if my hot tub is leaking?” 

Still, I could tell that a significant drop in the water level was noticeable, and I couldn’t tell if it was a leak or the level lowered because of natural causes such as evaporation. 

Over time, however, I have gained enough experience to tell the difference between a leak and other causes. 

I can also inspect and tell the leak source for proper action when fixing it. 

Keep reading to find out how you can tell if your hot tub is leaking.

Let’s get started!

How Can I Tell If My Hot Tub Is Leaking?

You can tell if your hot tub is leaking if you notice more than a 2-inch drop in the water level over a seven-day duration. A leaking hot tub can also be detected if one sees water pooling around the hot tub base when the jets are running. Water loss in a hot tub is normal, provided it doesn’t exceed an inch in one week. 

As a result, you may need to keep adding an inch of water every week to maintain the same level constantly. 

However, it is not necessary to constantly maintain the same level, but you might want to measure if you’re suspecting the possibility of excessive water loss. 

Excessive water loss means a leak, which is anything exceeding two inches. 

How Do I Check My Hot Tub For Leaks?

One method you can use to check whether your hot tub has leaked is to turn off the power, open the equipment compartment and check for apparent pooling or leaks. Also, check around the hot tub for an abnormal amount of water. Then, inside the cabinet, if there’s moisture, investigate further.

If your spa has a foam-filled cabinet, I advise digging away the soggy foam to find the leak causes. 

You can also check for leaks by filling the hot tub with water and allowing it to drain with the power off. 

After complete draining, try examining the parts just above the water level like the jets for leaks. 

I also use dye or food coloring to pinpoint the source of the leak. In this case, you will notice the leak location by observing where the dark water is coming from. 

These methods have worked perfectly for me in the past in identifying a leak. I have also found the method effective because of its simplicity in identifying the leak location and its culprit. 

What Would Cause A Hot Tub To Lose Water?

Plumbing leaks could be a cause of water loss in a hot tub. Specifically, rotten seals on the pumps could be the cause of the loss of water in your hot tub. In addition, loose or broken connections, pipes, unions, tees, and elbows could also cause water loss. The loss can also result from leaking jets or cracked hot tub shells, which is why they need an inspection. 

Small water losses are caused by evaporation due to the surrounding temperatures or the water temperature. 

Very little loss of water occurs from splashing when using the hot tub.

However, these two sources are common and not considered a cause for alarm. 

Why Is My Hot Tub Leaking From The Bottom?

Leakage at the bottom could be resulting from the pump, with the specific leak locations being either the wet end volute, union, or the shaft seal. It could also result from the filters and the plumbing components. If you suspect the leak is coming from the bottom of your system, inspect any of these suggested components.

Leakage from a hot tub should be a cause for alarm. But you should never panic. It is least likely that the shell has a problem.

Besides, you will easily spot and fix the issue without requiring technical assistance or special skills. 

So, let’s ponder why your hot tub could be leaking from the bottom. 

hot tub insulation2

Where Do Hot Tubs Usually Leak?

The common sources of leakage from a hot tub are usually the union fittings on either side of the heater. The pump could also be a common source of the leak on a hot tub. Therefore, you can quickly locate the exact cause of the leak by removing the side panels and locating where the drip is resulting. 

Here’s a link to Amazon with a bunch of hot tub fittings that you may find useful.

The Heater

The exact leak caused on the heater is usually the assembly manifold. 

The heat assembly manifold has a pressure switch, a heater, and other components. 

You will identify this as a long silver tube located on the underside of your component’s control box. It connects to the pump on the left side for most hot tubs for water pumping into the heater. 

It then comes out from the other side and goes back to the hot tub. 

These gaskets are common causes of the leak, which you must check when inspecting the heater for leaks. 

The Pump

A pump is the most common place where you are likely to find leaks on your hot tub. 

I highly recommend turning the power off before you commence to inspect the pump to prevent electrocution risks. 

It would be best to look under the pump for any signs of leakage. You could also look for rusts or water spots on the motor as indicators of leaking pumps. 

Pumps operate under high pressure. As a result, it is common to have worn-out seals. 


There are three primary valves on a hot tub: diverter valves, shut-off valves, and air control valves.

 The most prone valves to leakage are the diverter and the shut-off valves because they control water and not air. 

Shut-off valves help stop the water flow to facilitate servicing of the equipment without necessarily draining the hot tub.

The leak from diverter valves could be resulting from the dry or worn-out O-rings. 

If there are additional valves on your hot tub, ensure to inspect them all to ascertain that they are not the cause of the leaking problem. 

For example, the knife-style valves are designed with a gasket between both halves, bolted together. 

I would recommend inspecting the gasket for such a case because it can be a common cause of leaking. 

Union Fittings

Union fittings are located around the heater and the pump. As a result, they tend to become loose as time passes by. 

The common causes of loosening these components are vibrations or changes in the water temperatures. 

If you notice loosened union fittings, tighten them by hand. Experts discourage using a wrench in tightening the fittings because it could be damaging. 

Union fittings are usually two pieces that screw together and then threaded to screw into the opposite fitting. Each of the pieces has a rubber gasket. 

Unfortunately, the constant hot water can cause them wear or breakage over time, leading to leakage when such an issue happens. 

Fortunately, that’s not a difficult or expensive fix for you to worry much about. 

Hot Tub Shell

The majority of the hot tub shells are difficult to leak because they are made of strong fiberglass that prevents breaking. 

As a result, most cracks and blisters on the surface are usually cosmetic and never cause leaks. 

The common causes of leakages related to the shell will usually be related to jets or other components related to the shell. 

Nevertheless, it doesn’t mean that a hot tub shell cannot have a crack that would cause leaking. But it will always be easy to spot, even when the hot tub is empty

If you have tried all other ways of finding the source of the leak and have not been successful, I would advise that you drain and look for cracks on the shell. 

However, this should be the last step because it is the least likely cause of leaking.

Pipe And Jet Connections

The points of connection for jets and pipes act as areas of weakness. This should also be among the first suspects for excessive water loss in the hot tub. 

Your jet could be leaking because you have a failed gasket. 

Depending on the level of damage, replacement might be needed. Talk to your local dealer or the manufacturer to know the appropriate type of gasket to buy as a replacement. 

What Do I Do If My Hot Tub Is Leaking?

If your hot tub leaks, remove the side panel to locate the leak. You will then treat the leak based on its cause, such as gluing new shut-off valves, greasing the diverter valves, and replacing the worn-out gaskets. 

A leak might be inevitable for the hot tub owners. However, you might panic if this happens to you for the first time. But if you know what to respond to such an issue, it would never cause you panic because you will easily locate and resolve the issue without calling a technician for help.

The hot tub plumbing components and the leaking unions should be tightened by hand because using a wrench could cause breakage. 

If the problem is coming from the heater, replacement should be done by changing the pressure switch or the union gaskets, while the pump will be repaired by changing the wet end and the seal. 

If you need to disassemble the heater or the pump for repairs, you should start by switching off the electricity. 

If you see a major leak marked by gushing water, it would also be best to drain the hot tub to repair the leaks easily. 

Interestingly, most newer hot tubs will come with gate valves on either side of the heater and the pump. As such, you can close them easily to disassemble the desirable components without the need for draining the entire hot tub. 

If the sealing repair fails, I would recommend buying new housing. If you spot minor cracks or small leaks in pipes, you should treat them using a sealer. 

I would also recommend checking if your hot tub is still under warranty before you commit to fixing a leak. However, your hot tub could be leaking because of its age. 

There would be no point repairing a hot whose lifespan is over because the costs might be too high with the problem being recurrent. 

spa tool kit

How Much Water Loss Is Normal In A Hot Tub?

Water loss in a hot tub is normal, especially if it evaporates. The water loss will be acceptable if it averages an inch every week. Therefore, you might be required to add more water to your hot tub from time to time, depending on the loss that has taken place.

Evaporated water would require replacement because water will not remain at the same point you put it over time. 

If you want to ascertain the water loss rate, I would recommend marking the current level and measuring the new level after a week. This will determine if it is within the recommended limit. 

Does Fix A Leak For Hot Tubs Work?

Yes, one of the products that can resolve hot tub leaks is Marlig Fix-A-Leak. But it is most effective on the leaks at the jets and least effective on those that occur at the cracked PVC pipes. 

Fixing a leak for hot tubs works, especially for the minor cracks and leaks on the unions, pipes and connections, and other components. Seals are applied on the leaking surfaces to prevent further occurrence. 

The amount of sealant used depends on the size and location of the leak. Small and minor cracks will require as little as an 8-ounce bottle of the product. More of the product would be required for severe leaks. 

From my experience, the fix-a-leak product will usually hole which bare larger than 1/8 inches in diameter. 

How Much Does It Cost To Fix A Hot Tub Leak?

A hot tub repair by professionals can range between $200 and $1500. However, a higher margin could be attained when the repair will require accessing encased jets in the foam in the underside of the hot tub. 

However, you can make most of the leaks on a hot tub without incurring any costs associated with hiring a professional. I have done that on several occasions for minor leaks and cracks. 

Sometimes you can inspect your hot tub and feel that it would be necessary to purchase a new blower, control box, new pump, or topside down panel. 

These components are expensive to purchase and install, but you can easily replace worn-out ones if you understand these options.

The basic repair and maintenance for hiring professionals will be between $150 and $200. Finding repair companies willing to work on the portable hot tubs might be difficult. 

The majority will prefer to work on the in-ground hot tubs because they are easy to work on and can be charged a higher amount. 

How Do You Fix A Broken Hot Tub Pipe?

The first step in fixing a broken hot tub pipe is disconnecting electricity. When the leaking pipe has a shut-off valve called the gate valve on either side, you should start by closing them off. Failure to do so might force you to drain the hot tub entirely before working on it. 

Sometimes you might have an easy task of unscrewing the leaking pipe from the fittings if it is short for replacement. However, if this is not the case, be ready to cut and glue the added part. 

The leaking part of the leaking portion of the pipe should be cut using a hacksaw. You should then use PVC couplings to replace the existing solid pipe with fittings and pipes. 

Ensure to wear disposable gloves and allow adequate ventilation, applying a thin PVC premier coat to the outer ends of the pipes and the inner hubs of the fittings. 

You should then apply a thicker PVC cement coat over the primmer. You will accomplish this by pushing the pipe and fittings together, holding them in place for about 30 seconds, and releasing them. 

Proceed to open the gate valves if they were closed during the repair initiation and allow the glue to dry for about two hours before filling the hot tub. 

You should turn on the power immediately the water level reaches half of the hot tub. The jets should also be started after the water levels cover them to speed up the healing process of your hot tub. 

Maintain the heat of the water by leaving the hot tub cover. 

How Can I Tell If My Hot Tub Is Leaking: Conclusion

how can I tell if my hot tub is leaking

So, how can I tell if my hot tub is leaking?

A hot tub commonly leaks at the pump. However, leaks can also happen in the shell, connections, heater, valves, and the unions’ fittings. 

The least likely location of the leak is the shell, and I would recommend inspecting this component the last. 

The average water loss is usually about an inch in a week, usually caused by evaporation. However, the leak-related water loss exceeds two inches. 

You should switch off the electricity if you think your hot tub is leaking so that you can locate the leak. 

Most of the hot tub leaks are fixable by applying a sealant. 

However, if you choose to hire a professional to fix your hot tub leak, you will incur anywhere between $200 and $1000 or even $1500 if the hot tub cabinet is leaking.

I hope this article on leaking hot tubs was helpful.

Thanks for visiting

James Brockbank