Hot Tub Not Turning On? (Causes and What to Do)

hot tub

When you can’t get into your hot tub, you may be wondering what is wrong. Age, use, and wear and tear can take their toll on your hot tub.

If you can’t safely perform this maintenance yourself, you should call a professional.

Check the circuit breaker and pressure switch. If you find that the pump is malfunctioning, it is probably time to replace it.

If these steps aren’t working, you can still try a few other troubleshooting steps.

Troubleshooting a hot tub

If the hot tub is not turning on after a few minutes of waiting, there may be several factors at play. The first cause is likely the heating element. The heater will not heat the water unless it detects voltage.

The heater is connected to the control box by wires, so you’ll need to disconnect the heater and reconnect it before troubleshooting the issue. Another reason is a tripped GFCI (ground fault circuit interrupter). Resetting the GFCI will restore power to the spa.

A broken heating element

Heating problems are a common cause of hot tub problems and are usually simple to fix. A broken heating element or a malfunctioning thermostat may be the culprit. In this case, you’ll need to repair or replace the heating element.

If this still doesn’t solve the problem, you can try to troubleshoot the problem yourself.

Otherwise, contact a professional to reset the control panel. A broken thermostat can also be the cause of a hot tub not turning on.

If you’ve installed a topside control panel, check the thermostat. It may be faulty or incompatible with the circuit board. In some cases, the display may not turn on.

A reset of the system should resolve the issue. If the display is truncated or isn’t displaying a temperature, then the sensor may be plugged into the panel or has a dirty connection. If the problem persists, you may need to replace the control panel.

The high limit switch is another common cause of a hot tub not turning on. In this case, the heating element is not receiving enough voltage.

A high limit switch is a faulty switch. Another cause is a low water flow. Loose wire connections or incorrect voltages may also cause this problem.

If none of the above methods solve the problem, call a professional for further assistance. Hot tubs are complex machines that contain many safety mechanisms.

Checking the circuit breaker

One of the first things you should check is whether the circuit breaker is set to “on.”

When the GFCI switches trip, the tub may not be receiving any power. If the breaker is set to “off”, the problem may be with the circuit breaker itself. To check if the GFCI switch is set to “off”, push the breaker towards the OFF position and flip it back to “on.”

This should restore power to the hot tub and may solve the problem temporarily. If the breaker is still not reset, you should consider replacing the receptacle or moving further from the spa.

You should also check for corrosion in the components, which can affect the water chemistry and damage the spa.

If the GFCI has tripped, there’s a possibility that the electrical components inside the hot tub are faulty. A defective heating element or a shorted circuit breaker may cause the problem. To test if this is the problem, disconnect the hot tub, and examine the circuit board. If the control panel is damaged, replace it if you can.

Otherwise, if the circuit breaker is not tripped, the problem may lie with the hot tub’s circuit board.

If you’re having trouble finding the problem, you may want to contact a licensed electrician to check the wiring system of your hot tub.

Electricity is dangerous and working with it around water is risky. If you’re unsure, call a licensed electrician to perform the repair.

Most tripped circuit breaker issues are caused by a worn-out breaker. Lightning strikes in the vicinity can also cause the circuit breaker to trip.

Checking the pressure switch

If your hot tub is not turning on, the problem may lie in the pressure switch. When the water pressure drops, the pressure switch shuts down the hot tub heater, but the water still flows through it.

In this case, the pressure switch could be broken or need to be replaced.

Checking the pressure switch may be an easy DIY fix, especially if you are comfortable working with electrical components. However, if you are unsure of how to proceed, you should seek out a professional for help.

The pressure switch controls the hot tub heater and is usually located inside the heating chamber.

The power leads connect to these elements. If these are not functioning, you may jump out the switch by connecting a jumper wire between the two brass screws or spade terminals.

Once the wires are connected, turn the switch to the left to reduce the minimum pressure required by the heater. You should then see the spa heating up.

If you’ve tried all the above solutions but still haven’t noticed a difference, it’s time to check the pressure switch.

This component is usually located on a PVC plumbing part adjacent to the spa pack, or directly mounted onto the stainless steal heater manifold.

If you’re having trouble turning the hot tub on or off, you may want to replace the pressure switch.

After determining the cause, you can start replacing the pressure switch. In most cases, pressure switches are adjustable and can range from one to five psi.

Sometimes, you can adjust the minimum required pressure by making micro-adjustments in the dial wheel or a small screw.

Some pressure switches have an adjustment screw, and you can turn this screw counterclockwise to decrease the minimum required pressure. The key is to adjust the adjustment screw just enough to allow the heater to turn On.

Checking the pump

If your hot tub has stopped working for no apparent reason, one of the first steps you should take is to check the pump. This pump is responsible for the circulation of hot water in the tub. It’s vital to keep the water level up to a certain height in order to keep the hot tub operating properly. To ensure your filter canisters are clean, remove them and check if there’s any obstruction. Clean them if necessary.

If the pump is not turning on, you may have an internal electrical problem. Checking the water filter and the jets can be easy to do, but be sure to refer to the manual for specific instructions. A water filter leaf trap can also clog the intake pipe and prevent the pump from working properly. If these steps don’t solve the problem, you may have a damaged impeller. In some cases, it may be necessary to replace the pump.

In other cases, the water level is too low and the circulation pump is malfunctioning. If this is the case, you can lubricate the bearings or replace them.

Checking the pump when the hot tub is not turning on, is important to prevent water heater failure. Once these steps are completed, your hot tub can begin to work again. Check the circulation pump first, as it’s crucial for proper water circulation.

If you can’t hear the pump when the jets are turned on, it’s possible that your pump is blocked. First, check the electrical connection.

If the power to your pump is off, you should contact a professional immediately. Otherwise, you can try a few other steps to fix the problem. And don’t forget to call a professional, if you’re unsure.

Checking the heater

If you are having trouble turning on your hot tub, it might be the heater. There are several ways to troubleshoot this problem.

Check the water flow in the hot tub and see if it’s getting warm. If not, the water flow may be too low and a defective pressure/flow switch may be the culprit. If this is the case, you can try the tips below or call a professional.

You may also want to check the thermostat. The sensor should read the same temperature as the water in the hot tub.

To test this, buy a test sensor set from an online store and insert it in a cup of warm water.

During the test, the sensor will not turn on or heat up, so you may need two people to watch the contactor. If the test doesn’t work, you can replace the sensor set.

If you’re using a multimeter, you can check the circuit by inserting the probes into the spa heater’s terminal. Generally, if it shows a high reading, there is a problem with the heater itself.

The breaker can also be defective. Check the wiring to ensure that it’s safe and functional. If you’re unsure of whether the heater has a blown fuse, consult a technician.


In newer spas, the thermostat is replaced with a temperature sensor. It plugs into the main circuit board of the spa controller, and the probe end slips into the thermowell.

If the temperature isn’t correct, it’s most likely the temp sensor. If this is not the issue, check the topside control panel. If it’s not responding to the controls, you might have a problem with the relay coil.