How to Fix OH Code on Hot Tub: Overheating Troubleshooting

Looking for how to fix OH code on hot tub?. Well, many hot tub users have encountered this error at least one or more times in their hot tub lifespan.

Hot tubs topside control panel can display different error codes for different problems the spa encounter. One of those codes is the OH, OHH, or OHS error code depending on the make of the hot tub.

These error messages are meant to draw your attention to what is going on in your spa.

The OH, OHH, or OHS error codes on your hot tub are meant to tell you there is an overheat going on in your tub and that means the temperature sensor has detected unsafe water temperatures of 108° – 118° F, and your spa is in an emergency cool down mode. The heater is shut off, and the circulation pumps and blower are turned on to help dissipate heat.

Now that we know what the OH error code on the hot tub represents, let’s look at what the possible causes of overheating error codes are.

 What are the Possible Causes OH Error Code (Overheat) in Hot Tubs?

Low Water Flow (LF, FLO)

There are several causes of overheating in hot tubs. The most common cause of overheating in hot tubs is low water flow ( LF, FLO). This happens when the water doesn’t flow fast enough through the heater, it then causes the heater to stay hotter, and the temperature of the water increases. This issue gets picked up by the temperature sensor or the high-limit switches.

here are some causes of low water flow in a spa.

• A dirty spa filter cartridge.
• Closed or partially closed valves or jets
• Low water level in spa, and skimmer is sucking air.
• The pump has an airlock, or has lost prime.
• The spa drain cover is obstructed or a pipe is blocked.
•  Overheat protection may occur if the pump is set to operate for extended periods.
• In extremely hot weather, check for proper cabinet ventilation.
• When the hot tub is in a filter cycle, make sure P1 low-speed is on.
• When the temperature sensor is not installed properly

Besides the above, there is still another cause of overheating in a spa.

Problem with Thermostat or High Limit Switches

If you have ruled out low water flow as the cause of your hot tub overheating, then another possible cause could be the problem with the thermostat or high limit switches. These components are used in older spa packs.

If there is incorrect thermostat calibration or the thermostat becomes too sensitive, it can cause an overheat.

Modern hot tubs have electronic sensor circuits, which makes them durable than mechanical switches. But this doesn’t mean that these modern circuits are not prone to failure. In fact, the relays, high-limit switch, and circuit board can also develop faults.

In most cases, the low water flow issue in newer hot tubs can easily be fixed by the spa itself, the spa will cool, reset and start again on its own.

However, Some control panels need a prompt from you to restart. For spas without digital controls, you may need to manually reset the high limit switch near the heater housing.

Also Read:

How to reset hot tub control panel

Hot Tub Overheat Symptoms

Hot tub temperature is the biggest determining factor in how long your soak duration will last. Sitting in a tub of water that is at 98 degrees is likely not to affect you as the temperature is in line with your normal body temp.

But if the temperature goes above that and role into three digits, then you are going to feel its impact on your body.

Our bodies perspire to release heat and this becomes difficult as they are exposed to a higher temp and this will require the body to take in a lot of water. If the body doesn’t get enough of the water, then the heat gets trapped within the body, thereby raising the internal body temperature.

Generally, the most obvious symptom of hot tub overheating is when steam is coming off the water.

Here are some of the symptoms of hot tub overheat. Some early signs of overheating include the following:

If you notice your hot tub is overheating, you should try and fix it as soon as possible to avoid undesirable situations.

Here are some steps to follow if you see OH, OHS, OHH, or HH blinking on your hot tub control panel.

Step 1:  Turn the Temperature Down

If your hot tub is running at a really high temperature, you may need to turn the temperature down. But there is a limit to how much temperature you can reduce through this process. This may vary from tub to tub.

The owner’s manual will indicate what to do. But some people recommend you turn the power off for the tub to take in cool air before you lower the temperature.

This may take hours and possible days for the water to cool down.  But hot tubs that have overheating issues tend to have low water flow issues.

Step 2: Open the Hot Tub Cover

Opening the hot tub cover will let fresh air help cool the high temperature down. Open the spa cover and let the spa cool down for 10 minutes, then touch the control panel to reset the circuits or a push red reset button on the air systems.

Keeping the cover off will help in air circulation and this will help with the cooling process. Just keep an eye on it to prevent leaves and other debris from entering.

Step 3: Add Cold Water to the Hot Tub

This is a quick remedy but not a lasting solution. If the tub is not full, you can add cold water to cool it down. But be careful not to add too much water as it will put a lot of pressure on your filter to work harder.