How to Identify & Find Replacement Spa Jets

Great practical question, spa jets are one of those parts that look simple but have several specifications that all need to match for a proper replacement. Here’s how to approach it:

Step 1: Identify what you have

Before searching for a replacement, gather these key measurements and details from the existing jet:

• Face diameter: measure the outer diameter of the visible jet face (the part you see from inside the spa)
• Body diameter: the diameter of the jet body that sits behind the shell (usually 2″, 2.5″, or 3″)
• Thread type: jets either twist-lock (rotate to remove) or snap-in (pull straight out). Knowing which you have matters for compatibility.
• Jet type: the most common types are:
  • Directional – simple, single-stream swivel jets
  • Rotary/Whirlpool – spinning jets
  • Pulsating – create a massage-like rhythm
  • Cluster – multiple small streams from one housing
  • Therapy/Diverter – large jets for targeted muscle relief

Step 2: Look for a brand or part number

Many jets have identifying information molded right into the plastic:

• Check the back of the jet body once removed
• Look for a brand name, part number, or series name stamped or embossed on the housing
• Common brands include Waterway, CMP, Balboa, Jacuzzi, and Pentair

If you find a part number, that’s your fastest path to an exact replacement.

Step 3: Check your spa’s documentation

Your spa’s owner manual or parts diagram (often available online by searching your spa brand + model + “parts diagram”) will list the exact jet models used. This is especially helpful for proprietary jets that only fit a specific brand’s shell.

Step 4: When there’s no part number

If the jet is unmarked or too degraded to read, you’ll need to match by measurements:

• Remove the jet completely and bring it (or good photos of front, back, and side) to a pool/spa retailer
• Measure face diameter, body diameter, and note the thread/lock style
• Match the jet type (directional, rotary, etc.)

A caliper is more reliable than a tape measure for this job, since sizing tolerances are tight.

A few things to keep in mind

• Jets are often not cross-compatible between brands, even if they look similar and measurements are close. A Waterway jet body won’t necessarily accept a CMP insert, for example.
• You can sometimes replace just the inner insert (the spinning or directional part) without replacing the full body housing. This is cheaper if the housing itself is intact and undamaged.
• Color matching can be tricky with older spas since manufacturers discontinue colors. Gray, white, and stainless are the most universally available.
• When in doubt, replacing all jets at once makes sense. If several are failing, you’ll get a uniform look and save yourself repeat shopping trips.

The most important measurement is the body diameter; get that wrong, and the jet simply won’t fit the shell hole. Get that right, and everything else is much easier to narrow down.