Why Is My Hot Tub Jet Pressure Low?

Low jet pressure could be due to a clogged filter, airlock in the plumbing, or a malfunctioning pump. Clean the filter and check for air in the system.

Common Causes of Low Jet Pressure in Hot Tubs

1. Airlock in the Plumbing Lines

One of the most frequent reasons for low or no jet pressure is an airlock. This happens when air becomes trapped in the plumbing lines, especially after draining and refilling your spa.

Signs of an airlock:

• Weak or no water flow from jets
  

• Pump is running but no movement in the water
  

2. Dirty or Clogged Filters

Over time, your filters collect dirt, oils, debris, and even mineral buildup. If they become too clogged, water can't circulate properly.

Check your filters if you notice:

• Water pressure slowly decreasing
  

• Dirty water or murky appearance
  

• Increased noise from the pump
  

3. Blocked or Dirty Jets

Sometimes, the jets themselves are the problem. Mineral deposits, hair, or debris can partially block them.

Symptoms include:

• Some jets work while others don’t
  

• Jets shoot water at an angle or inconsistently
  

4. Low Water Level

If your water level is too low, air can get sucked into the system, reducing pressure.

Check for:

• Water level falling below the intake line
  

• Bubbling noises or inconsistent jet flow
  

5. Pump Problems

Your pump is the heart of your hot tub’s circulation. If it's malfunctioning, you’ll definitely feel it at the jets.

Watch for:

• Strange pump noises
  

• No water movement despite the pump being on
  

• Error messages on the control panel
  

6. Closed or Partially Closed Valves

Some hot tubs have slice or gate valves in the plumbing system. If these are closed or partially open, water flow will be restricted.

You may notice:

• Low flow only in certain areas
  

• Sudden loss of pressure after service or repair
  

How to Fix Low Jet Pressure: Step-by-Step

1. Check and Refill the Water Level

Make sure the water reaches the correct level, usually just above the highest jet. Low water can introduce air into the lines.

To do this:

• Turn off the power
  

• Add clean water using a hose
  

• Restart the system and see if pressure improves
  

2. Remove Airlocks

Here’s how to purge trapped air:

• Turn off the hot tub
  

• Loosen one of the pump unions slightly to let air escape (be ready for a bit of water)
  

• Tighten the union once only water comes out
  

• Restart the system
  

Alternatively, turning jets on and off or switching between settings may help push air out naturally.

3. Clean or Replace the Filters

Take out the filters and inspect them closely.

• Rinse thoroughly with a hose
  

• Use a filter cleaning spray for deep grime
  

• Soak in a solution if there’s heavy buildup
  

• Replace filters every 12–18 months
  

4. Inspect the Jets

Take a close look at your jets.

• Remove and rinse them with warm water
  

• Use a soft brush to scrub mineral deposits
  

• Soak them in vinegar if needed
  

• Reinstall them securely
  

5. Open All Valves

Check under the hot tub cabinet for any closed valves. Make sure all gate or slice valves are fully open to allow unrestricted flow.

6. Inspect the Pump

If you’ve tried everything else, the pump might need attention.

What to do:

• Listen for unusual sounds like grinding or humming
  

• Make sure the pump is primed (no air inside)
  

• Check for error codes or blinking lights on the control panel
  

• Call a technician if the pump seems to be the problem
  

Tips to Keep Jet Pressure Strong

Preventing weak jets is easier than dealing with it once it starts. Follow these maintenance tips:

• Clean filters monthly or more often if usage is high
  

• Drain and refill your spa every 3–4 months to prevent buildup
  

• Use a pre-filter on your hose when refilling to avoid metals and minerals
  

• Shock your water weekly to kill organics that clog lines
  

• Avoid bath oils or heavy lotions before entering the spa

• Inspect jets and valves regularly to catch problems early