An electric water heater typically controls the temperature in most hot tubs. When the temperature exceeds the desired temperature, the thermostat shuts off the heater. But there can be different reasons a hot tub can overheat. Also, individual hot tub components can overheat.
What causes a hot tub to overheat?
The most common cause for hot tubs to overheat is a sensor malfunction. However, faulty plumbing or other electrical problems can also cause a hot tub to overheat. Prolonged use and weather conditions can also cause a hot tub to overheat. Before further troubleshooting steps, check the temperature setting and the timer function.
This blog post, I list the most common overheating issues, how to troubleshoot, and how to fix them. Some of the issues are easy to fix. Some are more difficult and could even require help from a professional.
- 1 What Causes a Hot Tub to Overheat?
- 2 Hot Tub Overheating Symptoms
- 3 Spa Overheating Troubleshooting
What Causes a Hot Tub to Overheat?
There can be several causes for a hot tub to overhear. The three most common, with some tips to fix them, are:
- Temperature Set Too High: The problem could be from the wrong temperature setting. The temperature setting is the first thing you should always check if your hot tub is overheating. Somebody can have accidentally changed it, or a software issue could have triggered if you have a more complex temperature control unit. Check and adjust the temperature and see if this solves the problem.
One small tip: check the timer function as well. I had a client that had accidentally set a recurring timer to raise the temperature during part of the day. But when he checked the temperature setting, the timer was already finished, and the setting was back to the previous temperature.
- Electrical Problem: An electrical faulty within or around your tub can cause it to overheat. If you suspect an electrical problem, turn off the hot tub immediately, particularly when you also smell something. If your hot tub uses a wall plug, remove it from the socket. If you do not have experience with electrical systems, I recommend calling a professional. Electrical issues can be hazardous, particularly in combination with water.
- Hot Tub Sensor Problem: A problem in the hot tub sensor can also cause it to overheat. You can check if the sensor works well by lowering the water temperature setting. Check with a thermometer what is happening. If you do not notice a difference, there is a high chance that you have a faulty sensor. To make it harder, also, when the temperature does change, the sensor can still be defective. Replace faulty sensors immediately.
Of course, more issues can cause a hot tub to overheat. These include:
- Heating element: A fault in the heating element(s).
- Poor ventilation: The hot tub contains several components that will heat up when used. Similar to a car engine heating up when running. This applies to a lot of components like the pump. When the hot tub is poorly ventilated in areas with those components, they will get hotter and hotter. This can lead to plastic or other components like the insulation starting to smell. It also often results in increased wear and tear.
- Lack of maintenance: If you do not regularly check and maintain your filters, they can clog. This means that the pump has to work harder. This can lead to the pump getting hotter as it is cooled less well. Also, other hot tub components can deteriorate with a lack of proper maintenance.
- High temperature: If the air temperature is excessively high, it can lead to the hot tub overheating. In this case, lower the temperature and check if this helps.
- Maximum temperature: The hot tub is at its maximum temperature
No matter what's causing your hot tub to overheat, it is essential to fix the problem immediately. This is because overheating can lead to severe and irreparable damages. Another way to fix the overheating hot tub is by turning down the thermostat and allowing the hot tub to cool off before you turn the heat on.
Consider adjusting the ventilation if you notice condensation buildup around the hot tub or the spa cover. You'll also need to adjust the ventilation if you notice too much moisture leaking through the air jets.
Electrical problems could be a result of faulty wiring. It is worth mentioning that faulty wiring can cause an overload leading to the hot tub overheating. Turn off the hot tub and call a professional when you notice a wiring issue.
Hot Tub Overheating Symptoms
All hot tubs are susceptible to overheating the water, and this is because they require a lot of water to regulate temperature. Also, hot tubs thermostat do not usually measure temperature accurately, especially if it goes above 104 degrees Fahrenheit. Most hot tubs are generally not designed for use in places with hot temperatures because it's not easy for thermostats to control the temperature in these regions.
The most common symptoms of an overheating hot tub include the following:
- Heating elements stay on even when not in use
- Increase in electricity usage
- Steam coming off the water
The best way to handle these symptoms is by turning down the thermostat and removing the spa cover for proper ventilation. Ideally, your hot tub temperature should be around 97 to 104 degrees Fahrenheit. Consider placing a thermometer in your hot tub if you're not sure how hot the water is. You may need to check the heater or pump if the temperature is above 120 degrees.
Aside from being too hot for your body, another reason why it is important to keep the temperature within satisfactory limits is that too high a temperature can cause bacteria growth. This is surprising because it is generally believed that bacteria cannot thrive in hot temperatures. However, too hot temperature can promote the growth of some bacteria, and this can lead to health concerns.
Spa Overheating Troubleshooting
As mentioned earlier, an overheating hot tub could result from different issues or a combination of several. It is important to check all the potential causes whenever you notice your hot tub is overheating. When you see the hot tub display displaying OH, OHH, OHS, turn it off immediately. This means there is overheating issues. Your particular model can show something different on the display. Check your manual for this.
Do not turn on the hot tub until you're done troubleshooting. When your spa or hot tub is overheating, you can use the following troubleshooting steps:
– Hot Tub Overheating troubleshooting: Weather
It is normal for a hot tup temperature to rise above the normal range during the summer. It will happen even sooner if the hot tub is in the sun. Some components get hot when in use, like the pump. When the outside temperature is also hot, they have a harder time getting rid of excessive heat.
If you're in an area where the outside temperature is really hot, you might need to open the hot tub's access doors. This will help the heat dissipate more easily. Reducing the filtration cycles and placing the hot tub in economy mode will also help lower the temperature. I also recommend shielding the hot tub from the sun. In the sun, some materials can get extremely hot.
– Hot Tub Overheating troubleshooting: Filters
Your hot tub could be overheating because the filter is dirty. The dirt will clog the filter, and the water is not flowing freely. This can cause a buildup of heat in your hot tub or individual components like the heater or pump. Check the filters and ensure they are not dirty and not clogged.
Also, check the open shut-off valves if they are closed to prevent the water from becoming excessively hot.
– Hot Tub Overheating troubleshooting: Water level
The water level could be another reason why the temperature of your hot tub is rising uncontrollably. Your hot tub can get hotter if the water level is too low. Check the level of water, and ensure that it's up to the recommended level. Add more water when needed, and see if this solved the problem.
– Hot Tub Overheating troubleshooting: Power outage or lightning
Power outages can cause problems to any appliance, also to a hot tub. This is why it's important to check your hot tub after a power outage. Similar to lightning striking close. It does not happen that often, but it can affect the programming of your hot tub and lead to overheating issues. Check your hot tub heating cycles, and reprogram it if necessary. Lighting striking really close can even damage the computer.
Reprogramming your hot tub will include lowering the temperature. Your hot tub may be overheating because the temperature setting is too high. Lowering the temperature can be effective, but it's important to note that there's a limit to how much heat it will help you remove.
– Hot Tub Overheating troubleshooting: Call a professional
Troubleshooting an overheating hot tub is not always easy. Some problems are easy to diagnose and fix. However, there are issues where the problem may be more technical than expected.
If you try all the tips, we have provided, and your hot tub still has overheating problems. Or you do not have a lot of experience with this kind of problem. I recommend consulting a professional hot tub technician. A professional can often quickly identify the fault and let you know what to do, and if needed, replace and fix the issue.