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Pump Union 400-4300 - Bubbles Supply

Pump Union 400-4300

Part #: 400-4300

$7.82
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 400-4300 pump union is a 45-degree angled plumbing fitting designed for 2-inch spa pump connections. This OEM union connects 2" FBT (female buttress thread) to 2" spigot fittings, providing a reliable seal at pump discharge points in most residential spa systems. The angled design helps navigate tight plumbing runs while maintaining optimal water flow.

Built to Waterway's exacting standards, this genuine replacement union ensures exact fit compatibility with original equipment. Bubbles Supply guarantees same-day shipping on in-stock orders and backs every union with our comprehensive 1-year warranty for complete peace of mind. When installing, hand-tighten the threaded connection first, then use a strap wrench for the final quarter-turn to achieve proper seal without over-tightening the plastic threads.

Exact part number

400-4300

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • 2-inch spa pump union
  • 45-degree pump union
  • angled union fitting
  • union elbow

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

Technical specifications

Union size
2 inch
Port type
45-degree angled

Plumbing notes

  • Union size: 2 inch
  • Port type: 45-degree angled

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:

  • Water leaking at pump discharge connection
  • Cracked or broken pump union fitting
  • Stripped buttress threads causing slow drip or weep
  • Union won't seal properly after repeated tightening
  • Plumbing disconnecting from pump discharge port

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

Before you buy — quick checklist

  • Confirm your existing union is 2-inch FBT (female buttress thread) — measure thread diameter before ordering
  • Verify the angled orientation — this is a 45-degree fitting, not a straight union
  • Check whether your pump discharge uses a spigot-style connection to mate with this union
  • Inspect the mating pump port for thread damage before installing a new union — a damaged port will cause the new union to leak too
  • Confirm this is the discharge-side union, not the suction side, as those fittings differ

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

  • Waterway 400-4300 45-degree pump union
  • O-ring (union face seal)

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

Warranty

1 year 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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