The 4 Most Likely Reasons Your Hot Tub is Losing Water


Losing water in your hot tub can be a frustrating experience. Although it’s typical for hot tubs to lose 1 inch of water per week, there is likely an issue with your hot tub if it is losing several inches of water. If you’re struggling to find the reason for your hot tub’s sudden water loss, you have come to the right place. Today, we’ll cover the top 4 reasons your hot tub is losing water.

There are several reasons for a hot tub to lose water. The most common reasons include the following possibilities:

  • Evaporation
  • Running the hot tub during the winter
  • A leak in the hot tub
  • High hot tub usage

If you’re unsure how to determine what is making your hot tub lose water, have no worries! Read on to learn the reasons why your hot tub may be losing water, and how to solve the issue.

1. Evaporation

One of the most common reasons for hot tubs to lose water is evaporation. Generally, hot tubs lose 1 inch of water each week due to evaporation. In some cases, your hot tub may lose as much as 2 inches or more, especially if you keep your hot tub’s cover off.

While it is normal for hot tubs to evaporate water, it can become an issue when too much water evaporates. When water levels are too low, the hot tub’s equipment is at risk of becoming damaged. Additionally, low water levels make soaking in the hot tub a less enjoyable experience.

There are many factors to consider when deciding how to solve the rapid evaporation in your hot tub. For instance, if your hot tub’s temperature is set too high, the hot tub will evaporate quicker. For this reason, it’s important to keep your hot tub temperature in the range of 100°F and 102°F.

If you live in a dry climate, your hot tub is prone to evaporate faster than those in humid climates. For best results, it is recommended to keep a cover on your hot tub whenever it’s not in use. In addition to preventing evaporation, a cover will prolong the lifespan of your hot tub’s equipment and improve the water quality.

2. Running Your Hot Tub During the Winter

Because most hot tubs are designed to run year-round, many homeowners enjoy taking a soak in their hot tub during the colder months of winter. While running your hot tub during the winter may be an enjoyable experience, it can quickly become a nightmare when the hot tub begins losing water.

There is a reason hot tubs may lose more water during the winter than during the warmer months. Because the water is warmer than the outside temperature, hot tubs are prone to evaporate faster. As a result, your hot tub may lose twice as much water during the winter as it does during the summer. In some cases, it may lose more than 2 inches of water a week.

While it can be frustrating to deal with a hot tub losing water, there is no reason to give up your winter hot tub soaks. By properly covering your hot tub, you can prevent water from evaporating when not in use. Remember to also keep the cover on while the hot tub is heating up.

3. A Leak in the Hot Tub

When a hot tub suddenly starts losing water, it may be caused by a leak. Leaks can occur in a wide range of places, including the pump, the jets, the heater, and even the hot tub shell. Because it may be difficult to determine where your hot tub is leaking, it is important to check all of these areas.

A Leak in the Pump

The hot tub pump is one of the most common places for leakage to occur. Before examining the pump for a leak, make sure to turn off the pump’s power. Because much of the hot tub’s equipment is connected to the pump, you may want to turn the entire hot tub off as well.

There are three places that may leak in the pump. These areas include the shaft seal, the unions, and the volute. If it is the shaft seal causing the leak, the seal can easily be replaced. Fortunately, a broken shaft seal does not require the entire pump to be replaced.

The union fitting is a three-part connector located at the entrance and exit of the hot tub’s pump. If the union is causing the leak, you may need to tighten the union fitting. Additionally, you may need to adjust the o-rings of the union fitting. If these adjustments do not fix the leaking, you may need to replace it with a new one.

If it is the volute leaking, it will likely need replacing. Because the volute is where the impeller is housed, it is important that any leaks are immediately solved. If the pump still leaks after replacing the volute, you may need to replace the entire pump.

A Leak in the Jets or Connections

The jets, as well as all other connections, are common places for leaks to occur in hot tubs. When checking the connections for leaks, make sure to examine the pipes, jets, and any other connections in your hot tub.

While some connections can be tightened or sealed, others may need a full replacement in order to function properly. Certain connections, such as the gasket, require specific parts of the correct size.

A Leak in the Heater

A hot tub’s heater is composed of a pressure switch, the heater itself, and other components to make the heater run properly. As these components become older or damaged, they may develop cracks, which in turn will cause leaks. While some of these parts can be replaced or repaired, it may be best to replace the entire heater once it begins leaking. Depending on what is causing the leak, you may be able to repair the heater rather than replacing it.

A Leak in the Hot Tub Shell

Another place to look for leaks is the hot tub shell. Although the shell is crafted with several layers of strong, durable materials, it is possible for it to leak, especially if it is of old age. In many cases, the shell itself may not be leaking, but the connections attached to the shell are leaking. You may need to tighten or replace certain connections in your hot tub. If the shell itself is damaged, you may need to patch it with a seal for hot tubs.

4. High Usage in Hot Tub

Simply put, the more your hot tub gets used, the more likely it is to lose water. Not only will the hot tub evaporate due to the cover being kept off, but some of the water will get soaked into people’s swimsuits and hair. In addition, the more people use your hot tub, the greater the chance water gets splashed out of the spa.

While there is no solution for stopping water from escaping due to high usage, there are a few ways to keep water levels high when not in use. Immediately after you exit the hot tub, secure the cover on top to prevent further evaporation. Additionally, if the water level went down after being used, you may use a garden hose to top off your hot tub water. It is recommended to add more water to your hot tub every 1 to 2 weeks, or as needed to raise the water level.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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