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2-1/2" ID x 2-3/4" OD O-Ring 6500-816 - Bubbles Supply
Exact Fit

2-1/2" ID x 2-3/4" OD O-Ring 6500-816

Part #: 6500-816

$2.27
In stock — ships today
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Also replaces

6500-816
1-year warrantySame-day ship before 3pm CTPerfect Fit Guarantee30-day returns

About this seal/gasket

This genuine Sundance Spas O-ring creates a watertight seal for 2" pump unions in Sundance and Vico spa systems. Measuring 2-1/2" inner diameter by 2-3/4" outer diameter, this OEM replacement part (6500-816) ensures reliable operation and prevents costly water leaks at critical pump connections.

Built to Sundance's exact specifications, this O-ring delivers the precise fit your spa requires for optimal performance. At Bubbles Supply, we guarantee an exact fit with same-day shipping on in-stock parts, plus our comprehensive 1-year warranty for complete peace of mind. When replacing pump union O-rings, always inspect the union surfaces for damage and apply a thin layer of silicone lubricant during installation to ensure proper sealing and extend component life.

Exact part number

6500-816

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • 2-inch union O-ring
  • 6500-816
  • pump union gasket
  • pump union O-ring
  • union face seal

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

Fits these brands and models

Compatible brands

Sundance SpasVico
Not sure if it fits your spa? Send us a photo — we'll confirm before you order

Technical specifications

Union size
2 inch pump unions

Plumbing notes

  • Union size: 2 inch pump unions

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 union connection
  • Weeping or dripping at union fitting after tightening
  • Slow drip that worsens under pump pressure
  • Visible mineral buildup or cracking around union O-ring seat

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

Before you buy — quick checklist

  • Measure your existing O-ring — confirm 2-1/2" ID x 2-3/4" OD before ordering
  • Inspect the union body and union nut for cracks or damaged seating surfaces — a new O-ring won't seal against a damaged union
  • Confirm this is a Sundance or Vico system using your spa's equipment label or owner's manual
  • Check whether the leak is at the union face or elsewhere in the plumbing before replacing this part

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

Install difficulty: Easy — DIY-friendlyTypically 15-30 minutes

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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