Troubleshooting Common Problems with Hot Tubs

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  • 1-2 hours
  • Beginner
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For hot tub owners, one of the things that can get them through a long and grueling day in or out of the office is the thought of a nice evening soak in their hot tub. But that plan can be ruined if the tub, or spa, isn't working correctly. Common issues that can occur after just a few years into your spa ownership include the heating element not working, the GFCI tripping, or even worse, nothing working at all.

Proper maintenance can help you prevent some of these problems from occurring, but if they do happen, most of them are not too difficult to fix yourself. We'll help you troubleshoot a few of the most common hot tub problems so that you can get it back up and running quickly.

The GFCI Trips

A common problem is powering a hot tub back up after cleaning. Often, during the cleaning process, the GFCI will trip and shut the hot tub off. This can also happen at other times, such as when it's in heat-up mode. To determine what's causing this, begin unplugging a few of the most common troublemakers.

With your owner's manual in hand or on your phone or tablet, open your access panel to your control panel and pump. Identify where your heater, Ozonator (if so equipped) and your air blower parts are.

To begin troubleshooting, start with the heater since it's the most common cause of a GFCI tripping. To do this, unplug the heater. Most heaters will be connected to the control box via plugins. If it's not plugged in, it will be connected by wires. To unplug, disconnect these wires. Once the heating element is unplugged or disconnected, restart your hot tub by plugging it back in. If the GFCI doesn't trip again, you've found your problem and you'll have to replace the heating element.

If it still trips, it may be your Ozonator or your air blower. Following the same method as above—unplug or disconnect first the Ozonator and then the air blower. After you unplug each one, check to see if the GFCI still trips once it has been disconnected. If it no longer trips, you know which one is causing the issue and which one to replace.

If the heater is the cause of the trip, order a new heating element and replace it before starting it up again. For the Ozonator, you can leave it disconnected and still run your hot tub without issue and replace it when you're able (or never). And lastly, if it's the blower, you'll need to order the part and wait for it to come and be replaced until you can use the hot tub again.

All three of these situations can usually be prevented by properly maintaining your hot tub. The heater and Ozonator are especially affected by chemical balance like the PH and alkalinity.

Hot Tub Won't Get Hot

The largest issue or complaint that is heard by spa repair people is that the hot tub doesn't heat properly. There are a few reasons a hot tub may not be heating as it should, and we discuss them below.

The most common problem and the easiest to remedy is that the heater is tripping. To see if this is your problem, locate the high limit switch, also known as the heater reset button, in your manual diagram. Find the red reset button and push it. If it clicks or an indicator light comes on that wasn't previously on—congratulations! You've fixed the problem.

As for how long the issue remains fixed—that depends on why it tripped. This is almost always due to a dirty or clogged filter that's restricting water flow. Allow the hot tub to run a few days with the old filter in place. If it still heats properly, pop in a new filter and you should be good to go. Also, make sure that all of your jets are open for maximum airflow, and that all jets are pumping water through them.

If it shuts down again, it may mean that the switch needs to be replaced. But before you replace it, check to be sure it isn't the heating element itself that's causing the problem. With the spa running and jets on, turn the thermostat all the way up. Using a multimeter or amp meter, check to be sure that the heating element is reading at approximately 15 amps for a 110-volt hot tub, and 25 amps for a 220 volt. To ensure that you get an accurate reading, place one lead on one of the heater element posts and the other lead on the other post. If the amp test shows an improper voltage or nothing at all, it's time to replace the heating element. If the heating element tests out properly, then replace the high limit switch.

There may be other reasons your hot tub is not heating properly. These above are just the two most common ones. An electrician or spa repair person may be needed to help you further troubleshoot.

Nothing Works—Help!

The worst hot tub problem is when nothing is working at all. Fortunately, it's not necessarily the worst situation as far as repair goes. Troubleshooting this spa problem is going to be all about power: if it's getting it, and if it is, why isn't it working?

The first step is to check to see if your breaker tripped and if so, why. Either way, the next step is to get the ohmmeter out. Turn the breaker off, and if your hot tub has a disconnect box (usually wired up on the outside of your home in a spa control box), check the fuses. If they are registering proper voltage, turn the power back on and make sure that the required line voltage is at 110 VAC or 220 VAC (whichever your hot tub requires). If it's not one of these issues and all are reading properly, or if you're not getting the proper voltage, contact a licensed electrician to take further steps in determining the issue.

The second troubleshooting step when nothing is working is to test the GFCI, which is easy. Simply press the button on the GFCI unit that says "test" or "T." The "re-set" or "R" button should pop out—if it doesn't, then you have a faulty GFCI and it should be replaced. If when you press the reset button it just pops out again, you'll need to further troubleshoot. It could be that one of the items we spoke of under GFCI tripped earlier, or it may be due to fuses inside the spa control box (if it has them), burnt wires, or resetting the high limit switch we mentioned earlier.

These are just a few of the most common problems you may encounter with your spa, but fortunately, since they are the most common, hopefully, your fix is in there somewhere. All of these are relatively easy to do yourself and also rather inexpensive, depending on the issue. Most of these you can fix yourself, which will save you a lot of money. Fixing any electrical issues, however, should be left to a licensed electrician and in most states and for most warranties, it's required.

As for the cost of repairs here are some examples if you are a handy DIYer:

Heating elements: $50-70

Thermostat: $40-50

Ozonator replacement: $100-200

Pump: $200-500

High limit switch replacement: $20-30

Hot tub air blower: $70-175

Electrical work: $300-1000