If you are outside the United States and replacing a diverter valve, cap, or handle, the most important thing to understand is this:

The “1-inch” and “2-inch” rating has NOTHING to do with the size of the cap you see on top of your spa.

It refers to the plumbing size that glues into the valve body.

This causes confusion worldwide.

Let’s clear it up properly.

What a Diverter Valve Actually Does

A diverter valve redirects water flow inside your hot tub.

It allows you to:

• Send water to a specific seat
• Increase pressure to a cluster of jets
• Control a single foot jet
• Balance flow between two areas

That is why it is called a “diverter.”

1-Inch vs 2-Inch — What It Really Means

The size refers to the internal plumbing connection.

1-Inch Diverter Valve

• Designed for 1-inch plumbing lines
• Often used for neck jets or waterfall features
• Smaller water volume control

If you measure across the threads of a typical 1-inch diverter cap, you will usually get:

Approximately 1 5/8 inches across the threads

That measurement confuses people because it does not say “1 inch” anywhere near that number.

Again — the 1-inch refers to the pipe size glued into the valve body.

2-Inch Diverter Valve

• Designed for 2-inch plumbing lines
• Used for main jet pumps
• Controls large jet groups or foot jet systems

If you measure across the threads of a 2-inch diverter cap, you will typically see:

Approximately 2 3/4 inches across the threads

The cap width itself may measure:

3 1/4 inches
4 inches
Even 5 inches (depending on style)

But the thread width is generally consistent within that size class.

Brands That Interchange

Several major manufacturers use interchangeable diverter designs:

• HydroAir (original design)
• Waterway
• CMP (Custom Molded Products)

Many international spa brands use these same internal designs under different cosmetic caps.

For example:

Cal Spa
Dynasty
And many export brands

The cosmetic design may differ, but the thread dimensions often interchange.

Special Note: Jacuzzi®-Style Diverters

Some Jacuzzi® Premium style diverters measure approximately:

3 7/8 inches across the threads

They are still considered 2-inch class valves, but they do not label them that way.

Always measure thread diameter — not cap diameter.

Buttress vs Standard Threads (2-Inch Only)

Some 2-inch diverters use buttress threads.

If you remove your cap and see the word:

“BUTTRESS”

Then order a buttress-style replacement.

If nothing is marked, standard threads are typically correct.

In many cases they interchange — but if marked, match it exactly.

Common Diverter Problems

As spas age — especially in colder international climates — diverters can fail.

Common issues include:

• Cracked caps
• Worn O-rings
• Stripped threads
• Sticking handles
• Internal stem breakage

Another common issue:

The spa shell may sag over time, pulling the diverter body downward.

When that happens:

• Threads may not engage properly
• The cap may pop off
• The valve body may sink below the shell

In severe cases, the plumbing becomes rigid and replacement of the full valve body may be required.

Can You Upgrade the Look?

Yes.

As long as you match the thread width, you can often upgrade to:

• Six-spoke style caps
• Modern textured designs
• Different colors

Just remember:

Some 2-inch caps measure up to 5 inches across.

Make sure you have clearance before ordering.

International Customers — Verify Before Ordering

Shipping diverter parts internationally is expensive.

Before ordering, please send:

• A clear photo of the top of your cap
• A photo of the underside threads
• Measurement across the threads
• Brand of spa (if known)

We will confirm compatibility before shipment.

? Text: +1-772-800-5445
☎️ Call: +1-844-500-4645
✉️ Email: dvillanueva@spapartsnet.com

This prevents costly return freight and customs delays.

Final Advice From The Spa Guy

Do not order based on:

How the cap looks
What the dealer told you
Or what you “think” the size is

Measure the threads.

Match the plumbing size.

Send pictures if unsure.

That is how you get it right the first time.