Hot Tub FLO Error: Don’t Panic! Here’s How to Fix It

Have you just turned on your HotTub and seen the “FLO” error? If you’re here, that’s probably the case.

 

Don’t worry—I’ve got you covered! Let’s explore what an FLO error in your hot tub is and what could be the possible causes for it. 

 

What is a FLO Error?

 

A FLO error, which looks something like the picture below, is one of the most common hot tub errors. It will pop up on your control display and prevent the hot tub from heating up.

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A flow error is simply telling you that the spa pack in your hot tub can’t sense water moving through the heating element. As a precaution, it turns off the pump, so it will not heat anymore. 

 

This is done because leaving a heat pump on without water flowing through it could be a recipe for disaster.

 

Common Causes of FLO Errors

 

There are several reasons for what could cause a FLO Error in your Hot Tub. Some of these are pretty common, while others might be more technical. 

 

Here’s a list of the most common reasons for causing a FLO Error. 

 

Clogged Filter

 

This is one of the most frequent causes of the FLO error. A clogged filter prevents water from flowing to the heat source, resulting in the error. 

 

It’s very easy to check for this. All you need to do is remove the filter from your hot tub, power it down and power it up again, and see if the FLO error persists. 

 

If the hot tub turns on and runs without an error, the reason is the clogged filter, and you can have it cleaned or replaced. 

 

Lack of Water

 

This might seem like an obvious reason, but make sure that your hot tub is filled to the top. 

 

A lack of water in the Hot Tub will prevent proper water pressure from forming and, therefore, might cause the FLO error.

 

Airlock

 

If you’ve just filled up or made some changes to your setup and are getting a FLO error after starting up your hot tub, it might be because of an airlock. The airlock prevents water from flowing through the system and must be cleared out.

 

This is a relatively simple fix, and I’ve done another video on how to fill up your hot tub properly; you can check it out here.

 

Faulty Flow Switch/Sensor

 

This is less common, but is another reason for the FLO Error. If your circulation pump is running, and you have visible water movement in circulation mode, then a faulty flow switch is most likely the cause. 

 

These flow switches/sensors detect water flow and ensure that a constant flow is going through the system. 

 

To test this, find the switch or sensor on your system (look at your system diagram). Once you find it, you are going to jump the two connections. Basically, take a small piece of wire and connect the red and black inputs, which will bypass the flow switch. 

 

If the error disappears, then the issue is in the flow switch or sensor. 

 

Note: Only run the jumper between the two inputs if you can physically confirm the circulation pump is running and there is a flow of water into your hot tub.

 

Faulty Circulation Pump

 

Another culprit for the FLO error could be a faulty circulation pump. If your circulation pump is not working, you need to check for two things. 

 

The first is to check whether your pump is humming. If you hear humming but the pump is not running, it’s likely due to a faulty startup capacitor. Replacing that will fix the error. 

 

The second thing to check is if your spa pack is programmed correctly. If you’ve recently changed your spa pack or made other changes to, it might need to be reprogrammed. 

 

Check out this video on how to reprogram your spa pack.  

 

Summary

 

A FLO error can be annoying and confusing, but now you have a good idea of its possible 

causes and fixes. 

 

If the above solutions don’t work and you continue to get this error, you can always reach out to me, and I’d love to help! 

Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi

 

Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Today, I've helped over 1000 DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi