Why Is My Hot Tub Losing Water

Why Is My Hot Tub Losing Water?

It can be frustrating and concerning if you notice your hot tub is losing water. Water loss in a hot tub can occur for various reasons, and it’s essential to identify the problem’s source before it worsens.

In this blog post, I’ll explore some common causes of hot tub water loss and discuss how you can troubleshoot these issues.

Why Is My Hot Tub Losing Water?

Recently I have faced the same issue, like hot tub water reducing continually. While searching for a solution, I learned it is a common scenario.

I found out that evaporation is the most common reason. Hot tubs usually lose about 1 inch of water each week due to natural evaporation. However, running a hot tub during the winter can cause even more water loss due to the dry air.

Another reason for a hot tub leak is a loose or cracked lens in the light housing. Also, another reason is a worn rubber gasket on either side of the pump’s union fittings.

Although minor water loss is average, if you notice rapid water loss, it could signal a significant leak. It’s always best to check your hot tub for any signs of leaks and to seek professional help if necessary.


If evaporation is a natural process, it can lead to significant water loss, especially during the winter. I’ve experienced a loss of 1 inch of water every week due to evaporation.

Sometimes the rate can be higher when the cover isn’t tight-fitting, or the tub is heavily used. So, if you’re losing water in your hot tub, you should check if it’s due to evaporation or other issues.

To minimize evaporation, you can invest in a quality and well-fitted cover. Also, turning the temperature down to a degree or two can lessen evaporation levels. Finally, try to minimize splashing while using.

Running the Hot Tub During Winter

Hot tubs lose more water during the colder months due to evaporation. According to Campbell, with the lowest temperature and dry air, steam is created faster, which causes the water level to decrease in the tub.

However, you still need to run your hot tub regularly. It helps circulate water and prevent freezing in the lines.

You should not keep your hot tub empty during winter. It freezes and may eventually affect the pump, plumbing, and heater. (Paul Wylam)

“An empty hot tub in winter can freeze and damage the plumbing, pump, and heater, which can all lead to costly repairs,” says Paul Wylam of Proficient Plumbing & Heating.

I usually don’t recommend running the pump for a long time. Also, keep an eye on the temperature sensor. Besides, I add water as needed when the water level seems low.

I recommend draining and refilling the water a little early before winter begins. This could minimize the risk of damage due to water freezing. Also, turn down the jets when the tub is not in use.

Do not forget to clean the circulation pump filter every 30 days. It helps avoid clogs and poor water circulation that could lead to water freezing in the hot tub.

A Leak In The Hot Tub

Leaks can happen in various parts of your hot tub, such as the pump, fittings, or even the shell. To prevent significant damage, locate and fix the issue immediately.

Signs of a Hot Tub Leak can be tricky to spot. Some of the most apparent symptoms include water pooling around the tub, sudden drops in water level, and damp or soggy spots on your property.

To check for leaks, turn off the power supply to your hot tub and drain the water. Afterward, check the pump, unions, and wet end volutes for any signs of leakage. The most common cause of hot tub leaks is a failed rubber o-ring, seal, or gasket.

Another simple check is to mark the water level when the hot tub is off. Also, monitor the level over a couple of days when the hot tub is on and off. If the water level drops equally in both scenarios, then there may be a crack in the spa’s shell.

For a better level of your hot tub, you can read our guide about properly leveling a hot tub like a pro.

Finally, If you can’t find anything, don’t hesitate to call a professional to help you locate and fix the leak.

Where to Check for a Hot Tub Leak?

A list of possible places to find leaks in your hot tub.

The Pump

This is one of the most common locations. Turn off the pump and feel around for dripping water.

Or, place a finger underneath the rinse line to see if that’s where the leak is coming from. Hot tub pump Leaks can mainly come from three different places

  • Shaft seal
  • Union
  • Volute

Shaft Seal

A shaft seal can fail if the pump is operated without water or when the valves are shut. When these seals break, the water usually comes from the back of the volute.


The union has an o-ring in the middle, which connects the two halves of the union. When the union is improperly unscrewed, the o-ring can get replaced. It could result in leakage problems.

The second type of leakage may happen when the threads of pipes are deformed because of heat or if the pump runs without water.


The volute ruptures if you leave the pump out in cold temperatures while the tub is filled with water. The pump can also break when the valves are closed while running.

The Jets or Connections

A bad gasket in the jet body sometimes causes leaky jets. Gaskets will eventually break down over time because of hot tub water.

Also, when an o-ring needs replacing in the unions that connect the pump to the plumbing, you may check these connections for any signs of water seeping out.

If you find out that the water level of your tub is decreasing when you are filling the tub, you can check the jets for leaks.

The Heater

The heater might be the culprit if your hot tub loses water even when the pump is off. Look for water on or around the heater to indicate a leak.

The Hot Tub Shell

While it is rare, it can happen. If you notice colored water flowing out of a jet or seeping to the outside of the shell, you may have found the source of the leak.

Now, you can proceed to repair. Remember to always turn off the power before attempting any repairs. Feel free to call a professional if you need help with what to do.

How Much Water Loss is Normal In a Hot Tub?

From my experience and some research, I found that it’s normal for a hot tub to lose around 1 inch of water per week due to evaporation. It may go up to 2 inches and is still considered normal. This can vary based on the frequency of usage and water temperature.

However, if you’re losing more than that or noticing a sudden increase in water loss, there could be a leak in the hot tub.

This is when you need to take action promptly to further stop the issue. Start with searching for leaks or ask for technician assistance.

Should I Add Water To My Leaky Hot Tub?

Yes, you can add water. Since hot tubs usually lose 1 inch of water per week, try adding a similar amount to your tub.

However, adding water may not solve the issue if there is a leak. Getting a professional to check your hot tub for leaks and repair any damages accordingly is best.

Besides, continuously adding water can dilute the chemicals in your hot tub and affect its pH balance. This can lead to skin irritation and bacterial growth.

While adding water to your hot tub is tempting, you should address the root cause of the problem and get it fixed as soon as possible.

What To Do While Waiting for Professional Help To Arrive?

So, you’ve discovered that your hot tub is losing water and suspect that there might be a leak. What should you do while waiting for professional help to arrive?

First, turn off the power to your hot tub and drain the water to the level of the leak to avoid any electrical issues. Keep a close eye on the water level and refill it if necessary. This helps to prevent your pump from running dry.

It’s also a good idea to try and locate the source of the leak. Check for any visible cracks or holes in your hot tub shell, and inspect the heater, pump, and plumbing for any signs of damage or corrosion.

When in doubt, it’s always best to wait for a professional to assess and repair your hot tub. Trying to fix the leak yourself could end up causing more harm than good.


Overall, there are a few reasons why your hot tub may be losing water, but you should determine the cause to fix the issue.

Check your hot tub regularly for evaporation to leaks to ensure it’s running smoothly. Remember that a small amount of water loss is average, but if you’re losing more than two inches of water per week, there may be a more significant issue.

If you suspect a leak or any other problem, you can try to fix it yourself, but you should have the proper knowledge. Otherwise, call a professional for assistance.

Remember, regular maintenance and checking your hot tub can help prevent water loss and ensure your hot tub is working efficiently.


Hi, I'm Shimul, the founder of Pooltub Life. I'm excited about sharing the latest outdoor living trends with you. My goal is to provide you with up-to-date information that will help make your POOL & HOT TUB stylish and enjoyable. Read About Me More । Follow on Facebook

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