Regular hot tub water change or jacuzzi water replacement is an important part of proper maintenance. Clean and properly maintained water affects not only comfort during use, but also the operation of the filtration system, pumps and the entire pipe system.

It is recommended to change the water in a hot tub approximately 3 times per year. With proper hot tub water maintenance, regular checking of water values and the correct use of water care products, the water change may in some cases be less frequent. However, the water should be changed more often if the hot tub is used frequently or if the water becomes more heavily affected by external factors.

When is a hot tub water change necessary?

The water in a hot tub should be changed when you notice that, despite regular maintenance, it can no longer be kept in good condition. This may appear as cloudy water, an unpleasant smell, foaming, difficulty regulating the pH value or faster consumption of water care products.

A water change is needed more often in the following cases:

  • the hot tub is used by several people or very frequently,
  • residues of creams, oils, cosmetics or sunscreen enter the water,
  • the hot tub is placed outdoors and exposed to insects, leaves or dust,
  • the water becomes cloudy or algae start to appear,
  • the filter and water chemicals are no longer enough to maintain clean water.

In summer, the water is usually more heavily affected because users apply sunscreen more often, while the hot tub is also more exposed to insects and other impurities. For this reason, in warmer months it is especially recommended to always use a thermal cover when the hot tub is not in use.

Why is proper hot tub filling so important?

In a hot tub, water does not circulate only through the shell of the tub, but also through the filters, pipes, pumps and jets. Water is pushed through the filter by the circulation pump, which ensures water circulation and proper filtration.

If the hot tub is filled incorrectly after draining, air can remain in the pipe system. As a result, an airlock in the hot tub can form, preventing the water from circulating properly. In practice, this often shows as the circulation pump not working properly, no water flow, or the system being unable to push water through the pipes.

How to refill a hot tub correctly?

When refilling a hot tub with water, it is very important to fill it through the filter opening. This allows the water to fill the pipe system more easily and reduces the chance of airlocks forming.

Recommended procedure:

  1. Open the skimmer or the area where the filters are installed.
  2. Remove the filters from the hot tub.
  3. Push the garden hose used for filling into the filter opening.
  4. Start filling the hot tub through the filtration system.
  5. When the hot tub is filled to the correct water level, reinstall the filters.
  6. Only then start the hot tub or filtration system.

This method of filling helps the water first fill the pipe system and the pump, reducing the chance of air remaining in the pipes. This is one of the most important steps when changing hot tub water.

Airlock in a hot tub: what does it mean?

An airlock in a hot tub occurs when air becomes trapped in the pipe system or pump. Because of this, the circulation pump cannot normally push water through the system. The problem most often appears after a water change or after refilling the hot tub.

You can recognize an airlock by the following signs:

  • there is no water flow in the hot tub,
  • water does not circulate through the filters,
  • the circulation pump can be heard, but it does not push water,
  • no water comes out of the jets or the flow is very weak,
  • the hot tub may display a flow or filtration error, depending on the model.

If you notice that the circulation pump is not working or is not creating water flow after a water change, it is very likely that air has remained in the system.

What to do if the circulation pump does not work after a water change?

If there is no water flow after refilling the hot tub, first check whether the filters are correctly installed and whether the water level is high enough. If there is enough water, but the circulation pump still does not push water through the system, you can try a basic procedure for removing the airlock.

Step 1: remove the filters and start the pump several times

First, remove the filters from the hot tub. Then try to start and stop the circulation pump briefly 3 to 5 times. This allows the system to try to push the trapped air further through the pipe system.

In some cases, the airlock is released with this procedure and the water flow is restored.

Step 2: bleed the pump

If the water flow is not restored, the pump must be bled manually. Before doing this, the hot tub must be switched off so that the pumps do not run while the service area is being opened.

The procedure usually goes as follows:

  1. Turn off the pumps or the hot tub.
  2. Remove the service side panel of the hot tub.
  3. Find the pump where air is trapped.
  4. Carefully release the air through the bleed screw or the air bleed connection on the pump.
  5. When water flows from the pump without larger air bubbles, close the screw again.
  6. Restart the hot tub and check the water flow.

If you are not sure where the pump or bleed screw is located, it is recommended to consult a service technician before doing this. Incorrect opening or loosening of connections too much can cause water leakage.

How to prevent an airlock from forming?

The best prevention is correct hot tub filling. Every time you change the water, it is recommended to fill the hot tub through the filter opening, as this reduces the chance of air remaining in the pipes.

To avoid problems after a water change, follow these tips:

  • always fill the water through the filter opening,
  • remove the filters before filling,
  • do not start the hot tub until it is filled to the correct water level,
  • check the water flow after filling,
  • clean the filters regularly,
  • use the cover when the hot tub is not in use,
  • regularly monitor the pH value and the levels of water disinfectants.

Conclusion

A proper hot tub water change is important for clean water, good filtration performance and the long service life of the hot tub. It is recommended to change the water approximately 3 to 4 times per year, and more often if necessary, especially with frequent use, in summer or when the water is more heavily affected.

When refilling, it is very important to fill the water through the filter opening. This allows the pipe system to fill correctly with water and reduces the possibility of an airlock in the hot tub. If after changing the water you notice that the circulation pump is not working or that there is no water flow, first remove the filters and briefly start the pump several times. If this does not help, the pump must be bled through the bleed screw.

With the correct filling procedure and regular maintenance, you can avoid most problems and ensure that your hot tub works safely, efficiently and reliably. Read also how to correctly add chemicals to hot tub water.