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Pump Union 400-5680 - Bubbles Supply

Pump Union 400-5680

Part #: 400-5680

$15.32
In stock — ships today
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1-year warrantySame-day ship before 3pm CTPerfect Fit Guarantee30-day returns

About this union/fitting

The Waterway 400-5680 pump union is an essential plumbing connection designed for 2-inch spa pumps requiring a transition to 1-1/2-inch suction lines. This OEM replacement union fits Waterway spa pumps and ensures a secure, leak-proof connection between your pump and plumbing system. Featuring 2-inch FBT (female buttress thread) on one end and 1-1/2-inch slip connection on the other, this union accommodates the 2-inch spring configuration commonly found in spa installations.

At Bubbles Supply, we guarantee this Waterway union delivers an exact fit for your spa system, backed by our comprehensive 1-year warranty. With same-day shipping on in-stock items, you'll get your spa running quickly without compromising on quality. This genuine OEM part ensures compatibility and long-term reliability compared to generic alternatives. When installing, ensure all connections are hand-tight plus a quarter turn to prevent over-tightening that could damage the union threads.

Exact part number

400-5680

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • 2-inch to 1.5-inch reducing union
  • pump union fitting
  • spa pump union
  • suction union

Looking for an older part number? Check our supersession lookup tool

Technical specifications

Union size
2-inch FBT x 1-1/2-inch slip

Plumbing notes

  • Union size: 2-inch FBT x 1-1/2-inch slip

Need help measuring? Email hello@bubblessupply.com with a photo of your existing plumbing.

Common symptoms this part fixes

If your spa is showing any of these signs, this part is likely your fix:

  • Active leak at pump inlet connection
  • Water dripping from union body or nut
  • Cracked or brittle union from UV or chemical degradation
  • Stripped or cross-threaded union threads causing persistent drip
  • Union won't seal after repeated tightening attempts

Not sure if this is your problem? Try our diagnostic centre or .

Before you buy — quick checklist

  • Confirm your pump's suction port accepts a 2-inch FBT (female buttress thread) connection
  • Measure your existing suction line — this union transitions to 1-1/2-inch slip, not 2-inch slip
  • Inspect whether the leak is at the union body or the o-ring — if only the o-ring, you may not need a full union replacement
  • Verify this is the suction-side union; discharge-side unions are often a different configuration
  • Check that your pump is a Waterway brand unit — fitment on other brands is not confirmed

Reading the checklist now prevents 90% of returns. Worth the 60 seconds.

Install difficulty: Medium — Some experience neededTypically 30-60 minutes

What's in the box

  • Pump union body
  • Union nut
  • O-ring

If your order is missing any items listed above, contact hello@bubblessupply.com within 48 hours of delivery.

Warranty

1 year manufacturer warranty against defects

Covers manufacturing defects. Does not cover improper installation, normal wear, or accidental damage.

Warranty claims: warranty@bubblessupply.com

Perfect Fit Guarantee

Ordered with our help and the part doesn't fit? Contact us before installation. We'll resolve it with an exchange, replacement recommendation, or return approval.

Learn about our Perfect Fit Guarantee →

Shipping

We ship across the US and Canada. US orders ship from our US warehouse to US customers; Canadian orders ship from our Canadian warehouse to Canadian customers — no cross-border shipping, no surprise duties. In-stock orders placed before 3pm CT ship same day. Standard shipping $9.95 flat rate. Free shipping on orders over $200. Express options available at checkout.

Returns

30-day hassle-free returns on unused parts in original packaging. Contact us before returning to receive your RMA number.

Frequently asked questions

Check the Compatibility section above to confirm fitment for your spa brand and model. If your model is not listed, use our fitment selector at /pages/find-my-part or ask our parts AI for a personalized recommendation.

In-stock orders placed before 3pm CT ship the same day. You will receive tracking information by email as soon as your order ships.

We accept returns within 30 days of delivery for unused items in original packaging. Email returns@bubblessupply.com with your order number to start a return. Installed electrical parts cannot be returned for safety reasons.

Yes, all new parts come with a 1-year warranty against manufacturing defects. Warranty does not cover damage from improper installation or normal wear and tear.

Customer reviews

AI Fitment Assistant

Tell us your spa model and we will confirm this part fits before you buy.

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