How to Identify & Repair a Hot Tub Leak

Jennifer Rhodes

By Jennifer Rhodes · Updated

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Do you have a hot tub that you fear might be leaking? It's an infuriating and potentially costly problem that no one wants. But don't fret! We're here to help.

In this article, we will go through how to identify and repair several different kinds of common hot tub leaks. We’ll provide you with helpful tips and advice that will help you not only pinpoint the cause of the leak, but will also patch it up as well.

A simple trick to find the source of a leak

Finding and repairing a hot tub leak can be tricky, but there are a couple of simple tests you can use to identify the source of the leak:

The first is to add food coloring to the water. Let the spa circulate for a day or so, and then look for colored foam insulation around the tub (you will need to remove the side panels for this). This should give you a good idea of where the leak is located.

If you think the leak might be coming from the air lines, leave the valve closed so that it is not drawing air through, as this could prevent the leak from revealing itself.

If you don't have success with the food coloring method, you may want to put the tub up on blocks and fill it up to find out where the water is dripping from. This should help you locate the right general area.

Once you have identified the source of the leak, it's important to repair it as soon as possible to avoid possible damage to any spa components.

How to fix different types of hot tub leak

Knowing the specific type of leak in your hot tub will help you determine the best way to address it. Depending on the source of the leak, the fix could involve something as simple as tightening a few connections, or in some cases it could require replacing larger components.


The pump plays an important role in hot tubs as it is responsible for circulating the water around the entire system. Therefore, having a functioning pump is necessary for enjoyable hot tub experience. Unfortunately one of the most common hot tub issues is a leaking pump.

There are typically three causes of leaking pumps:

  1. Leaking shaft seal: A mechanical shaft seal that wraps around the spinning motor shaft and prevents water from leaking. It can fail if the pump was run dry or if valves are closed while the pump is running. To replace it, the wet end of the pump (volute) must be opened, the impeller removed, and the old seal half knocked out. A new seal half is then pressed fit into the volute and the spring half is slid onto the impeller.
  2. Leaking unions: Unions are large white rings that are threaded onto the pump to connect water inlet and outlet. They have two halves with an o-ring in between. A leaking union can occur if the o-ring becomes dislodged or if the threads have shrunken due to heat. Quick repair can be done by reseating or replacing the o-ring, or replacing the union half.
  3. Leaking volute: The volute, also known as the impeller housing, can become cracked due to freezing temperatures or water hammer effect. A cracked volute can lead to fast water leak and is easy to identify. It can be repaired by replacing the cracked volute parts or the entire wet end, including volute halves, impeller, diffuser and seal.

To fix the pump, you need to identify the source of the leak and repair or replace the necessary parts. In some cases, you may need an entire new pump.


Another common source of hot tub leaks is the drain. Make sure the drain cap has a gasket in it. If these gaskets are missing or bad, it won't matter how tight you get the drain—it will still leak.

As the factory drain on most spas is prone to failing, many spa owners prefer to use alternative methods of draining their tubs. Some of these can be significantly faster anyway.

Lights or jets

Lights or jets are yet more components of a hot tub that can be prone to leaking. Generally, these leaks can be fixed fairly easily by simply tightening the threads used to hold them in place.

However, if there are signs of wear along the seal, then the component may need to be replaced.


Pipes are an integral part of hot tubs and are used to move both water and air through the system. If a pipe becomes cracked or damaged, it can cause leaks, leading to a decrease in water level.

You can use Plast-aid to repair cracks in PVC pipes:

Plast-aid Multipurpose Repair Plastic - 6 oz Kit
Plast-aid Multipurpose Repair Plastic - 6 oz Kit
View on Amazon

This can be done as a simple DIY project in most cases. The two-part resin works to fill in gaps and form a bond with the material it is applied to. It is also waterproof which makes it perfect for hot tubs.


Hot tub shells are strong, but do occasionally develop cracks. If the spa shell does have a leak, Plast-aid can also be used to seal holes or cracks here.

This product can be used on acrylic or fiberglass spa shells, and it can even leave the shell stronger than it was before. This means you can usually fix your hot tub's shell yourself quickly and easily.

Why brand new hot tubs can leak

If you discover a leak in your hot tub, it’s important to investigate further, but don’t necessarily panic if it’s a recent purchase.

Brand new hot tubs can, unfortunately, be more susceptible to leaks than older ones. Why? In a new hot tub, it’s possible something didn’t get tightened properly and slipped through quality control.

Here’s the good news: As your spa is new, it’s most likely that it’s just a loose connection that should just need to be tightened or sealed to fix the leak.

If you see a crack in the shell, however, you should contact your hot tub store to assess the situation. Your shell should still be under warranty for issues like this.

With new hot tubs, it's a good idea to get help from the store where you bought the spa rather than try to fix it yourself, so you don't risk voiding the warranty.

Closing thoughts

If your hot tub is leaking, it’s important to identify the cause before attempting to fix the issue. Taking the time to diagnose it properly will save you time and money in the long run, whether you decide to get help with the repair or fix it yourself.

With the right tools and a little know-how, you’ll have your hot tub back to normal in no time!

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