Hot Tub Temperature Sensor Troubleshooting
If you're dealing with temperature fluctuations in your hot tub water, there is probably an issue with your temperature sensor.
Of course, you're probably not a hot tub expert, which is why you came here to find the right steps to fix your problem.
If you need to troubleshoot your hot tub temperature sensor, come dive in with us as we take you through our detailed troubleshooting guide.
Verifying Your Water Temperature
One of the first things that you need to do is verify that the water temperature on your control panel is correct. To do so, you can place a thermometer in your spa water to see if the temperature on the control panel has a discrepancy.
If there is a discrepancy, then you probably have a thermostat with a faulty sensor on it.
The majority of hot tubs have a sensor that can be found on the internal portion of the filter housing. You want to make sure that you push the temperature probe is flush securely into the thermowell. You also want to make sure that there are not any kinks in the capillary.
One of the most common reasons that a hot tub's temperature bounces around is that the thermostat is faulty.
Check Out Your Water Flow
Once you have verified your water temperature, you want to make sure that the water flow is not impeded in any way. To do so, you can check the filter to see if it is clean or not. You want to make sure that your water levels inside the hot tub are at the right height.
To prevent problems with flow, you want to make sure that the lines and the pump impeller are not obstructed in any way. One of the ways that you can get the best pressure coming from your jets is to make sure that you have a pump system that is working properly.
Test Out Your Heating Element, Switches, and Sensors
After you've checked out your water temperature and water flow, you need to inspect the other components. Start by looking at your sensors and switches. One of the first switches to look at is the high-limit switch, which you can find on the heater.
For those who don't know, the high-limit switch is a hot tub safety feature that will turn the heater off automatically when it reaches a maximum temperature.
If the high-limit switch gets to failure or is subject to improper adjustment, you might deal with excessive fluctuations in temperature. In some cases, your hot tub's heater might not end up working at all.
Similarly, you need to check the flow switch and the pressure switch. If either of these switches is too sensitive, or if one of them has gone bad, your hot tub's heater might end up malfunctioning.
We discussed the thermostat in the first paragraph. Your thermostat can also impact the ability of your hot tub to heat up.
You want to make sure that when adjusting your thermostat, that you adjust it with small increments. Start by checking to see if there are any loose connections and secure them if so. If the thermostat on your hot tub isn't working at all, you might need to replace it altogether.
However, if all of your switches seem fine, then you'll want to check out the heater element to see if it is still working. You can do so by checking out the voltage reading to see if your heater element has the right reading.
Check Out Your Heating Element
You can find the coil element in a housing assembly inside of your hot tub. The coil element is the thing that produces all of the heat in your hot tub, exchanging the heat to the water while it continues to flow through the tube.
The assembly is made up of a few components, including the limit switch. It is also necessary to know that the assembly can take on several different forms.
If you aren't getting any heat out of your hot tub, one of the major problems might be that the heating coil is burned out. In this case, the switches and the thermostat might not work in the way that they should. One of the main reasons that you might be dealing with reduced heat or low heat is that the water isn't flowing as it should, not that you have an electrical problem with your heater.
One thing that you want to do if your water isn't flowing optimally is check for any clogs or obstructions. If you're dealing with excessive clogging or buildup, the heating element might suffer from reduced efficiency.
The good thing is, you can test out your heating element without having to get in touch with any professionals. To start, you want to remove the heating element from its circuity. Start by disconnecting the two power leads on the heating terminals and use an ohmmeter to take your measurements. You will use the meter's test leads to measure the resistance between both of the terminals.
If you're dealing with a low reading, then it is more than likely you have a short-circuited bad unit. If you're dealing with a high reading, then you might be dealing with an open circuit that has limited conductivity.
Check Out Other Components
There are a few other factors you might have to consider if you think your temperature sensor is broken. One of the first things that you might want to consider is the temperature outside, as these could have a negative impact on the water temperatures that are inside of your hot tub.
You should also consider the fluctuations of daily outside temperatures and how they might affect your hot tub, as well as the ability for your hot tub to retain heat with the built-in insulation.
If you're dealing with a hot tub during the hot summers that gets really hot during the day and loses out on heat when it gets deeper into the winter months or cool evenings, then you might be dealing with a bad circulation schedule or poor insulation on the inside.
The inside of a hot tub can get hot pretty quickly. If your hot tub heats up way too fast, it makes it quite easy for your hot tub to overheat or fluctuate. Some other things that might raise the temperature in your hot tub include water circulation friction as it continues moving through the plumbing lines and pumps.
If you're dealing with a spa cabinet that is excessively warm, you might need to give it a bit more ventilation. On the other hand, if you're dealing with a spa cabinet that can't heat up enough, you might need to give it a bit more insulation.
When adding insulation to the inside of your hot tub cabinet, you need to be very careful. You could end up placing your insulation way too close to your spa equipment, such as your spa pump or your heater, which could be a fire hazard. Click here to learn more about how to insulate a hot tub.
Another thing that you can do if you're dealing with a lack of insulation is to purchase a higher quality hot tub cover. A good hot tub cover will have the right amount of foam density and will be fitted nicely to your particular hot tub model. You should pick your cover based on the climate that you live in.
It may be time to purchase a new spa cover if you notice that it is sagging, wearing out, or starting to get heavy due to taking on water. See the cover guy reviews for our recommended products.
Installation Safety
When installing heater elements, it is important to practice safety. One thing that you need to make sure to do is not to bend or twist the electric terminal. You als0 want to make sure that you prevent any air from getting in the plumbing, as dead air can cause your hot tub to overheat.
You also want to prevent your water from corroding your components if it gets too acidic. One of the best ways to do this is to keep your water balanced with the proper chemicals.
Lastly, you should not turn your heater on and off simultaneously throughout the day, as this can put a lot of stress and strain on your heater. One of the best things to do is set a timer for your hot tub to prolong the life of the heater.
How Do You Test a Hot Tub Temperature Sensor?
If you need to test out your spa temperature sensor, follow this step-by-step method.
Note that you will need an ohm meter before you start.
If you don't know where your spa temperature sensor is, you can start by using a thermostatic probe to detect it Typically, temperature sensors are placed within the hot tub housing or directly within the heater tube.
If you still can't find it, refer to the owner's manual.
- Start by shutting off all of the power for your hot tub using the spa pack and the breaker. If you don't shut your hot tub off ahead of time, you risk electrocution.
- Take your Ohm meter and put it on the 20K setting
- Find where the ends of the wires are and remove the plug from your board
- Take your meter leads and place them on the red and green wire
- Compare your finding to the Resistance Vs. Temperature table to see if your sensor is working correctly according to your hot tub specs.
How To Reset Your Hot Tub Heater
If you've gone through all of the testing steps and nothing is working, it might be something as simple as resetting your system.
If you're dealing with a spa heater that has stopped working or has tripped, then you might to simply reset it. If you need to reset the heater in your hot tub, follow these simple steps:
- Locate the high-limit reset switch on your hot tub. Typically, you'll be able to find this red button on a spa pack. However, in some cases, you might find it on your hot tub heater.
- When you press the high-limit button, it should click, letting you know that it is ready to go.
- Turn your hot tub on and observe it while it operates. If the hot tub isn't getting any power, then you may have tripped the GFCI outlet or the breaker panel switch.
- Press the GFCI outlet reset button or flip the switch on the breaker panel to give the hot tub the power it needs. Once done, turn your hot tub on. If your hot tub stops working or trips the minute that you give it heat, it is probably due to the onboard heater element. In that case, you might need to replace the heater altogether.
Final Thoughts
Many common hot tub problems are fairly easy to fix. Once you have figured out the source of your temperature problems, you can decide whether or not it is something that you are able to fix on your own, or an issue that you need to call a repair service for.
It is always best to contact your local hot tub dealer or distributor to get an idea of what kind of maintenance your hot tub needs depending on the particular problem that you're dealing with. Some repairs, especially in the electrical realm, will require professional solutions. This is also true if the repair requires you to replace an electrical component.
