High-quality hot tubs rarely have pump issues, but when they do, repair is typically the answer—not necessarily buying a new hot tub. If one day you discover that your pump is making a strange noise or not working at all, you can likely troubleshoot the problem on your own. Often, the pump is fine, but an airlock or a sensor issue is keeping the spa from running. But if the spa is leaking water, call your local dealer immediately so an experienced technician can evaluate the problem. If you attempt to fix it yourself, you may void your warranty.
Below is a list of some of the more common hot tub pump issues and the steps you can take to resolve them.
Hot Tub Pump Troubleshooting Made Easy
In many cases, a hot tub pump may not run because of other issues with your hot tub. Top spas, such as Caldera® spas, have failsafe and diagnostic tools engineered into them. If the spa senses a power supply or electronic system issue, for example, it will shut down automatically to avoid damage. This doesn’t mean that there’s an issue with the pump; it simply means that you’ll have to rule some things out to get to the root of the actual problem. As always when troubleshooting, have your Owner’s Manual handy.
On Caldera Utopia® Series spas, the logo light serves as a helpful and visible diagnostic tool. When the diagnostic logo light shines orange and gray, the spa water is within 2° Fahrenheit of the set temperature and ready to enjoy. When the spa senses an issue, the diagnostic logo light may turn off, blink, or the colors may flash independently. Specific logo light behaviors alert you to specific problems:
- A flashing orange light indicates a problem with the temperature sensor.
- No orange light means that water temperature is outside of 2° F of the set temperature.
- A flashing gray light indicates that the heater high-limit thermostat has tripped, meaning that the spa water is above an acceptable temperature range or that there is a flow issue.
- No gray light indicates that a problem has occurred with the power supply or there is an issue with the spa control box.
- If there are no lights whatsoever, the power to the spa may have been interrupted and needs to be restored.
In general, the best place to begin troubleshooting a hot tub is by checking the ground fault circuit interrupter (GFCI). When the GFCI detects an issue with the power supply, such as a ground fault or a short circuit, it cuts off all electricity to your spa. When that happens, it’s called “tripping” the GFCI. To reset the GFCI and restore power to the spa, simply press the GFCI’s reset button.
To troubleshoot issues with the temperature sensor, heater high-limit thermostat, and the spa control box, disconnect power to the spa by flipping the GFCI breaker, and leave off for thirty seconds. Once you return power, check the logo lights to see if that reset resolved the issue. If it did not, check for these other common culprits that prevent hot tub pumps from operating properly: a low water level, an airlock, and dirty filters.
Checking the Spa Water Level and Filters, and Removing an Airlock
Over time, your spa loses water due to evaporation and spillage that occurs with regular use. A low water level will cause the hot tub’s pump to struggle to create the pressure the spa jets need to function properly.
Additionally, dirty filters can block water flow and cause a similar issue. Most important, both issue triggers can also cause a heater high-limit trip that will render the spa unresponsive until it has cooled down or the issue has been addressed.
The ideal water level for your spa is about an inch above the highest jet. Always check the level when doing routine hot tub maintenance. Access the filters by opening the filter compartment, and then visually inspecting them to see if they are dirty. If they are, clean the filters as per your Owner’s Manual.
An airlock is another fairly common issue that can affect hot tub pump operation. When water is drained from a spa, air flows in to replace it. When the spa is refilled, some of that air may become trapped and act as a plug that keeps water from moving through the hot tub’s piping. If you turn on your spa, hear the pumps running, but see no water flowing from the jets, the most likely culprit is an airlock. Turn the spa off immediately to prevent damage to the heater and the pumps.
To remove an airlock, follow the steps below:
- Turn the spa on and set the heater to below ambient temperature to avoid damaging it.
- If your spa’s jets can be manually adjusted, open them up all the way and ensure that all diverter valves are in the open position.
- Set the jets on high for 10 to 15 seconds to force the air out of the pumps.
- If you see air bubbles emerge from the jets, leave the jets running to eliminate all of the air
- If you do not see any air bubbles on your third or fourth attempt, stop immediately and contact your dealer to arrange a service call if your spa is under warranty. If your spa is out of warranty and you want to attempt to troubleshoot further, follow the directions noted below.
If taking the above steps fail to remove the airlock, disconnect the spa from its power supply, remove the access panel, and locate the pumps. With Caldera spas, diagrams are included in the Owner’s Manuals. In a Caldera Vacanza® Series spa, you’ll find the main pump that powers the jets and a circulating pump that maintains the water’s condition and temperature. Above both is a PVC pipe and a fitting (a union) that joins the pipes to the water pump. Loosen the union (do not completely disconnect it) to release the air. Leave the union loose until water begins to flow from it. At that point, tighten the fitting, turn the spa back on, run the jets, and then check the union to make sure it isn’t leaking. If all is running well, replace the access panel.
Spa Professionals Perform Hot Tub Pump Troubleshooting and Service
If troubleshooting your hot tub pump doesn’t fix the issue, contact your local spa dealer for support. A hot tub service professional can perform a thorough hot tub pump check-up and diagnose each component of your spa. If your hot tub pump has worn out or has become damaged, a trained technician can replace it.
Your local dealer can also help you with regular maintenance and service. It’s just one of many ways that the network of Caldera spas dealers supports their customers.