How to Fix Airlock in Hot Tub: Signs, Causes, and Solutions

An airlock in a hot tub may sound minor, but it can stop your spa from working properly and even damage equipment if left unresolved. Many hot tub owners encounter this problem after draining or refilling their spa, when trapped air gets caught in the plumbing lines. This air pocket blocks normal water flow, leaving jets weak or completely nonfunctional. In some cases, the pump makes a hissing sound or shuts down, and you may even see error messages on the control panel.

Knowing how to fix airlock in hot tub systems is an essential skill for every spa owner. Airlocks are one of the most common problems after routine maintenance or seasonal restarts, and fortunately, they can usually be corrected with a few simple steps. In this blog post, we’ll cover what an airlock is, the signs to look for, step-by-step fixes, prevention tips, and when to call in professionals like Factory Direct Hot Tubs for repair or service support.

What Is an Airlock in a Hot Tub?

A hot tub air lock occurs when air gets trapped inside the internal plumbing after draining or refilling. This pocket of air prevents water from circulating through the pump and heater, which disrupts the normal function of the spa.

Most airlocks occur when:

• The spa has just been refilled without bleeding air through the filter canister.
• The water level dropped too low, allowing air into plumbing lines.
• Debris or clogs caused partial blockages that trapped air.

When air blocks circulation, water may stop moving through the jets, the heater may fail to turn on, or the pump may run dry. Running a pump without water flow risks overheating and long-term damage. This is why recognizing and resolving airlocks quickly is important.

Factory Direct Hot Tubs provides repair requests and service support to handle stubborn or recurring airlocks that DIY methods don’t solve.

Signs of a Hot Tub Airlock

Airlocks typically make themselves known quickly. Hot tub owners should be aware of these common signs:

• Jets not working properly – You may see reduced water flow or no water coming from the jets at all.
• Noisy pump – A pump running with trapped air often makes gurgling or grinding sounds.
• Visible bubbles in plumbing lines – Air pockets may release in bursts.
• Error messages – The control panel might show flow or heater errors.

Quick Symptom Reference Table

If you notice these issues after refilling, it’s almost always an airlock. The good news is that in most cases, it can be resolved in minutes.

How to Fix Airlock in Hot Tub: Step-by-Step

Step 1 – Burp the Jets

Start with the simplest method. Turn the hot tub on, cycle the jets, then turn them off. Repeat this process several times. This “burping” forces air pockets through the plumbing. You may hear hissing or bubbling as the air escapes, followed by the water flow returning to normal.

Step 2 – Release Air at the Pump

If burping doesn’t work, you’ll need to manually release air from the pump housing. Locate the union nut or bleed valve on the discharge side of the pump. Loosen it carefully until you hear air escape, then tighten once water begins to flow. Always ensure power is off when opening unions to avoid risk.

Step 3 – Use a Garden Hose in the Filter Canister

Place a hose into the filter canister and run water through the system. This forces air out of the plumbing and replaces it with water. This method is especially useful after a complete drain and refill.

Step 4 – Power Cycle the Spa

Shut down the spa at the breaker, wait 30 seconds, then restart. Many newer spas also feature a priming mode, which helps clear trapped air automatically.

Safety Tip: Never run the pump dry for more than a few seconds. Prolonged dry running can cause permanent damage to seals, impellers, or motors.

How to Prevent Airlocks in the Future

The best way to deal with airlocks is to prevent them from happening in the first place. Prevention starts with how you fill and maintain your spa.

• Always refill through the filter canister. This directs water into plumbing lines and reduces trapped air.
• Maintain proper water levels. Don’t let water drop below the filter opening, especially during heavy use.
• Fill slowly and steadily. Rushing a refill can create turbulence that traps air pockets.
• Regularly check filters and plumbing lines. A clogged filter can reduce flow and create conditions for airlocks.

Factory Direct Hot Tubs offers spring restart services and winterization support for seasonal spa owners. These professional services include proper refilling and bleeding of the system to minimize airlock risk.

When to Call a Professional for an Airlock

Most airlocks can be cleared with the steps above, but sometimes the issue persists. If:

• Jets still don’t work after multiple attempts,
• The pump continues making noise,
• Or the system repeatedly throws error codes,

…it’s time to contact a technician. Airlocks can sometimes signal other issues like a clogged filter, debris in plumbing, or leaks in the suction side of the system.

Factory Direct Hot Tubs makes it easy with repair requests, service calls, and free virtual consultations. Our in-house team provides seven-day-a-week service, ensuring problems are fixed quickly without voiding warranty coverage.

Conclusion

Airlocks are one of the most common problems hot tub owners face after draining or refilling. Fortunately, learning how to fix an airlock in hot tub systems is straightforward: burp the jets, release air at the pump, use a garden hose in the filter canister, or power cycle the spa. Prevention through proper refilling and maintenance is the best long-term solution.

When simple fixes don’t work, Factory Direct Hot Tubs is here to help with repair requests, service calls, spring restarts, winterization, relocation, and free consultations. Our experienced team ensures your spa is always ready to deliver safe, relaxing performance, no matter the season.

FAQs

How do I get rid of an airlock in my hot tub?

You can burp the jets by cycling them on and off, release trapped air from the pump union, or use a garden hose in the filter canister to push air through. These methods usually restore water flow in minutes.

How do I clear an airlock in my hot water system?

The principle is the same as with hot tubs: trapped air prevents normal flow. Opening bleed valves or releasing air from the highest point of the system will usually clear it. For household hot water systems, consult a plumber for safety.

How do I get my hot tub out of lock mode?

Lock mode is different from an airlock. Most hot tubs have a control panel lock function to prevent unauthorized use. Check your owner’s manual to unlock the keypad. If the jets still don’t work, the issue is likely an airlock instead.

How to find a blockage in a hot tub?

Start by checking filters for debris, then inspect visible plumbing lines. Reduced water flow can be caused by airlocks, clogged filters, or blockages in the intake. If the problem persists, a professional inspection is recommended.