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Pump Union 400-6010 - Bubbles Supply

Pump Union 400-6010

Part #: 400-6010

$19.95
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 Pump Union 400-6010 is a genuine OEM plumbing connection designed for spa and hot tub pump installations. This 2-1/2" female buttress thread to 2-1/2" slip union provides a secure, watertight seal between your pump and plumbing system, making pump removal and maintenance straightforward without cutting pipes.

Engineered to Waterway's exacting standards, this union features durable construction that withstands constant exposure to heated water and spa chemicals. At Bubbles Supply, we guarantee this is the exact fit for your system, backed by our 1-year warranty and same-day shipping on in-stock items. The female buttress thread (FBT) end connects directly to compatible Waterway pumps, while the slip end bonds permanently to your spa's PVC plumbing. Always verify your existing union's thread type and measurements before installation to ensure proper fitment.

Exact part number

400-6010

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • 2-1/2 inch FBT union
  • female buttress thread union
  • hot tub pump union
  • spa pump union
  • Waterway pump union

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

Technical specifications

Union size
2-1/2 inch female buttress thread (FBT) x 2-1/2 inch slip

Plumbing notes

  • Union size: 2-1/2 inch female buttress thread (FBT) x 2-1/2 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:

  • Leaking at pump connection
  • Union cracked or split from UV or chemical exposure
  • Stripped or cross-threaded union threads preventing seal
  • Pump cannot be removed without cutting pipe
  • Slow drip at pump inlet or outlet that worsens over time

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

Before you buy — quick checklist

  • Confirm your existing union uses female buttress thread (FBT) — not standard pipe thread or MPT
  • Measure your existing union: this is a 2-1/2 inch connection, do not assume size from pump body alone
  • Check whether you need one union (inlet or outlet) or two — most pump replacements require a matched pair
  • Verify the slip end will bond to your existing PVC pipe diameter before purchasing
  • Inspect the mating pump port threads for damage — a new union won't seal against a damaged pump port

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

Install difficulty: Easy — DIY-friendlyTypically 15-30 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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