Most expensive hot tubs that we buy at our home, like any other appliance, tend to develop some fault after few months of usage later on.
It can be a minor or a major fault.
But then, you get more concerned or worried about how to get these problems fixed up.
Actually, SN codes displaying on your hot tubs aren’t something to be really worried about.
It’s a minor problem that can be fixed in a few steps within a short while.
Sn codes can appear in different forms on your hot tub.
It can be shown as Sn, Sn1, Sn2, Sdn, etc.
No matter the form of display, they all refer to the temperature sensors located on the hot tub heater manifold.
It’s an indicator that either the temperature or high limit sensors are shorted or open.
It could also be a thermostat or voltage problem in your hot tub.
Like the OH error code or FLO error code on your hot tub, SN codes are water-flow dependent.
If there is not enough water flowing or water not flowing fast enough through the heater chamber, then the hot tub gets overheated.
After that, your hot tub enters the safety mode and it starts displaying the SN code.
If you want to fix the Sn code, then you need to first turn off the hot tub system from the power switch.
After that, try unscrewing the sensors from the heater manifold and unplugging the wire from the panel.
Then, check the wire and sensor face for any damage or corrosion signs.
After a few minutes, plug it back on.
You also need to check the hot tub filter cartridge and clean it regularly.
If the cartridge is damaged, then you need a new replacement hot tub filter.
Also, check for any broken valves and the skimmer if it is stuck with something.
Table of Contents
- 4 Main Reasons Behind SN Code Fault in a Hot Tub
- 4 Simple Steps to Fix SN Code Error in a Hot Tub
- FAQ Related to Fixing SN Error Code on Your Hot Tub
- What Does SnS Mean on My Hot Tub?
- Why Does My Hot Tub Say SN?
- How Do I Know My Hot Tub Sensor is Bad?
- 6 Important Steps to Follow to Test the Hot Tub Temperature Sensor
- 3 Easy Steps to Reset Your Hot Tub
4 Main Reasons Behind SN Code Fault in a Hot Tub
Before you start fixing Sn error codes on your hot tub, you should be familiar with the main causes of this error.
Because there are different reasons behind the Sn code fault and for that, you have to implement the appropriate solution as well.
The Sn fault code in a hot tub could be a result of any of the 4 following reasons.
Reason 1: Bad or faulty wires can cause issues by absorbing excess heat.
Reason 2: Loose plug or a bad connection to the hot tub
Reason 3: Insufficient water flow through hot tub heater
Reason 4: Hot tub Thermostat or voltage problems
You need to first find out the main reason from the above list that is causing the SN error code in the hot tub and then apply the right solution.
Sn code error means a high limit sensor or a temperature sensor is shorted or open.
And these issues could be caused by a loose plug, bad wire, or low water flow.
If you’re wondering how you can fix the Sn code on your hot tub, you should be aware of the causes of the error which I have already mentioned above.
Step 1: Clean or Replace Bad Hot Tub Filter
If the high limit sensor is open or shorted, your first step should be to clean or replace the hot tub filter.
Also, check that all jets are open and the drain cover is not blocked.
Ensure that the valves underneath the hot tub are all open.
Step 2: Check Hot Tub Valves and Impeller
Once all these checks have been carried out and the water still seems to flow less than normal, consider inspecting the hot tub.
Check for any broken valves and clogged impeller of your hot tub.
Step 3: Make Sure Skimmer Pipe and Pump Airlock are Working Fine
Look for the skimmer pipe and make sure it is not stuck with something.
Make sure the water level in the hot tub is filled high enough and be sure there’s no pump airlock.
Step 4: Finally Reset the Temperature Sensor
If the temperature sensor is open or shorted, locate the temperature sensor on the heater and you need to then reset it.
The high limit sensors and temperature sensors are found on the heater housing and have one or more wires connected to the controller.
Now, turn the main hot tub power off, unscrew the sensor and unplug the wires from the panel.
After that, wait for a few minutes before plugging it back in.
Make sure that the sensor face is not corroded and wires are not damaged before plugging them back.
And this is how you reset the hot tub temperature sensor and make it work again.
Recommended Articles for You:
FAQ Related to Fixing SN Error Code on Your Hot Tub
SnS refers to a sensor problem with the hot tub unit.
If your hot tub displays the SnS code, it simply means that the sensors are out of balance.
The SnS sensor problem can vary from brand to brand.
SnS code on some hot tub models refers to a temperature thermistor that senses the temperature of the water inside the heater.
The display may indicate a temporary condition if it alternates with water temperature of the hot tub.
It can even mean a total shutdown of the hot tub unit if the code is displayed as periodical blinking.
That is, SnS or even Sn code if on the display, is alternating with the water temperature.
If this happens, then it is a possible sensor out of sync message.
This shows that one sensor reads a different temperature than the other.
The system will then monitor the sensors for one hour and at this time the problem will resolve on its own.
If the SnS or Sn code flashes OFF and ON and does not indicate the water temperature, then it is a confirmed “Sensors out of sync” message.
In this case, if the system has verified the sensor to be out of sync with each other, then you might need to replace the worn out sensor with the new one.
If you find this process difficult to solve on your own, then I recommend to call a hot tub professional to handle the problem of servicing and repairing your hot tub unit.
Sn refers to a sensor syn that detects a high-temperature difference caused by low water flow through the hot tub heater.
If your hot tub controller displays the Sn error code, it means there’s a problem with the temperature sensors on the heater.
Typically, a display of Sn error code in your hot tub means the temperature sensor or high limit sensor is shorted or open.
It could also be an issue with the thermostat allowing the heater element to overheat or it could be a voltage issue.
It means that there could be an excessive voltage flowing through the circuit which can cause overheating of the hot tub.
Sn code is usually displayed at lower temperatures where the ohms changes per degree are at a higher temperature.
This problem can be fixed if you clean the water filter and check the pump to ensure it’s working appropriately.
You need to then reset the code if need be.
If you still get the SN code error while everything is working normally, then you certainly need to replace the old damaged sensors with the new one.
We will take an example here to better understand this issue.
Suppose, you set your hot tub heater to your desired temperature on the control panel; let’s say at 103° F.
After that, the temperature falls to 100° F before the heater goes on.
It keeps running until the water temperature reaches 105° F or the high limit switch trips.
The same thing happens when you set the thermostat and the water consistently gets hotter or cooler than expected.
In that case you may need to test some of the heater problems like verifying the water temperature.
Temperature fluctuation or discrepancy in temperature reading could be an indication of a bad temperature sensor thermostat.
It’s best if you run a test on your hot tub temperature sensor to know if it’s bad and needs a change.
6 Important Steps to Follow to Test the Hot Tub Temperature Sensor
Step 1: First, turn off the hot tub main power.
Step 2: Then, set ohmmeter to 20k.
Step 3: Find the ends of the wire and unplug them from the circuit board.
Step 4: Your meter leads should be placed onto the red and green wire.
Step 5: Compare the thermistor resistance and the temperature chart readings.
Readings to the temperature vs Resistance chart are provided by your hot tub manufacturer.
Step 6: A zero reading on the meter means your cable or hot tub sensor is bad or damaged.
Note that most hot tubs come with more than one temperature sensor.
Also, most thermistors and temperature sensors read around 10000 at 77°F.
And cold water creates higher temperature readings up to 50K and at the same time, 100 degrees F warm water produces lower readings.
If you see that your hot tub temperature sensor is not working properly and damaged then you need to get a new replacement for it.
You need to reset your hot tub control panel or hot tub heater in the following conditions.
1. If your hot tub has some minor faults like heater tripping
2. Your hot tub has stopped working completely
3. The control panel keeps flashing and showing different error codes.
Resetting the hot tub heater can be done using the high limit sensor reset switch.
Also, by checking breakers and GFCI outlets, you can resolve this issue.
I recommend to follow these 3 steps below to reset your hot tub heater successfully.
Step 1: Locate the High Limit Reset Switch
The high limit reset switch is a red reset button switch covered by a rubber nipple found in many hot tubs and may be located on the heater.
Press the button, it will click if it is tripped.
Step 2: Turn the Hot Tub On
Now, turn the main power of your hot tub and observe how it works.
If there’s no power to the hot tub, the breaker panel switch might be tripped.
Step 3: Restore the Hot Tub Power
For this step, simply flip the breaker panel switch on and power on hot tub again.
If the breaker trips again, the heater element might be faulty and needs to be replaced.
For the hot tub control panel, you can simply reset it by switching the hot tub off and then back on again after 15 to 20 seconds.
If the error continues, check the hot tub manual to find out what the problem is.
Even after that, you can’t restore the machine properly, then call a hot tub professional to reset your hot tub without any hassles.
You can also watch the following video tutorial on how to reset hot tub heater in few minutes to do it yourself.