How to Deal with a Hot Tub Air Lock

 

Have you ever tried to use your hot tub, only to find that the jets have stopped working? No water, no air—just silence.A hot tub without working jets is basically just a fancy bathtub, and that’s not what you signed up for!

So, what’s going on?

Many hot tub owners don’t realize that air locks are a common issue. When air gets trapped in the plumbing, it prevents water from circulating properly, which means your hot tub won’t function as it should.

Not only will the jets stop working, but chances are the heater won’t either. If there’s no consistent flow, pressure sensors and switches fail to activate. This can lead to error messages on your control panel, like PS1, PS2, PS Low (pressure switch problems), No Flow, or Air in System. No matter what the message says, it all points to the same problem—there’s air trapped in your system.

It’s important to know how to fix an air lock before it turns into a bigger headache! In this guide, I’ll walk you through the steps to remove an air lock and get back to enjoying your hot tub.

How Do I Know If My Hot Tub Has an Air Lock?

Identifying an air lock is easy:

• You turn on the pump, but nothing comes out of the jets.
• Only some jets are working, while others remain inactive.
• The jets are running, but the water pressure is weak.

Before jumping to conclusions, check that your pump is running properly. In a previous post, we discussed capacitor issues that might prevent the pump from working. If your pump is running, but nothing is coming out of the jets, you likely have an air lock.

If the pump is humming but not actually running, check out this post for troubleshooting steps.

How do I know if I have an Air Lock in my Hot Tub?

It is quite easy to tell if you have an air lock in your hot tub.

If you turn on your pump and there is simply nothing coming out of the jets. If you turn on your pump and only a couple of the jets are working. If you turn on your pump and the jets are working but there is no power in them. Then the chances are that you have an air lock in your hot tub.

We’ve seen in a previous post how the pumps may not be running properly and this can be a capacitor problem, so it is important to check that the pump is running correctly. If it is and there is nothing coming out of the jets, then it is an air lock. If the pump is humming and not running properly, then check out this post which might help.

What Causes an Air Lock in a Hot Tub?

Air locks can happen for several reasons:

There is a crack in the pump. The pipes and jets are dirty and clogged with debris. Air has entered the system and become trapped during filling. This is the most common cause by the way!

What Causes an Air Lock in a Hot Tub?

Air locks can happen for a few reasons:

• A crack in the pump.
• Dirty or clogged pipes and jets.
• Air trapped in the system during filling—this is by far the most common cause!

How to Fix an Air Lock in a Hot Tub

Good news—fixing an air lock is easier than you think! Here’s how:

“Burp” Your Hot Tub

This method is simple and surprisingly effective. Think of it like burping a baby—you’re just coaxing the trapped air out!

1. If your hot tub has a control panel, look for the priming mode. If it doesn’t, don’t worry—you can still do this manually.
2. Turn the jets on low for 15-20 seconds.
3. Switch the jets to high for another 15-20 seconds.
4. Repeat until the jets run smoothly, without irregular flow or excessive bubbles.

Release Air Directly from Your Hot Tub

If burping doesn’t do the trick, you may need to manually release the trapped air. Here’s where to check:

1. Air Bleed Screws on the Pump

• Look for air bleed screws on the pump itself. Some models have one, while others have two.
• Before loosening the screws, close the gate valve on the discharge side of the pump. (You’ll usually find this after the Spa Pack.)
• Loosen the air bleed screw(s) until you hear a hissing sound. A little water coming out is normal—that’s a good sign!
• Tighten the valve, reopen the gate valve, and test the pump.

2. The Hot Tub Filter

• Turn off the pump.
• Remove the filter cover. Some filters have a bleed screw—if yours does, use it to let the trapped air escape.
• Air tends to get stuck in the filter area, so this is an easy fix to try!

3. Loosen the Union Nut on the Pump

If you still have air trapped in the system, try this:

• Close the gate valve on the return side (the one after the Spa Pack).
• Slowly loosen the union nut on top of the pump. You should hear a hissing sound—that’s the air escaping!
• Once the hissing stops and water starts dripping out, tighten the nut again.
• Reopen the gate valve and test the pump.

Be Patient—Persistence Is Key!

Sometimes, there’s more air trapped in your system than you think. If the first few attempts don’t work, keep trying.It might take a few rounds, but you will get the air out eventually!

What If Nothing Works?

If all else fails, your last resort is to drain the tub and start fresh.

1. Once the tub is nearly empty, run the jets for 2-5 seconds. (Be careful—pumps shouldn’t run dry for too long!)
2. Do the same with the blower—just a quick burst of 2-5 seconds to clear any trapped air.
3. When refilling, pour water through the skimmer instead of directly into the tub. This helps prevent air locks from forming.

Final Thoughts

Air locks can be frustrating, but they’re easy to fix with the right approach. Whether you’re burping your tub, releasing air from the pump, or draining and refilling, a little patience goes a long way.

By following these steps, you’ll have your hot tub back in action in no time!

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.

Fast forward to 2025, I've helped over 1400+ 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