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1/2" MPT Flow Switch Q-12DS-C2-BEACH - Bubbles Supply

1/2" MPT Flow Switch Q-12DS-C2-BEACH

Part #: Q-12DS-C2-BEACH

$201.73
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About this flow switch

The Harwil Q-12DS-C2-BEACH is a 1/2" MPT pilot duty flow switch designed for Beachcomber spas and other compatible hot tub systems. This OEM-quality sensor monitors water flow through your spa's plumbing system, ensuring proper circulation and protecting your equipment from damage caused by low or no-flow conditions.

Built to Harwil's exacting standards, this flow switch features reliable pilot duty operation and durable construction that withstands spa water chemistry and temperature fluctuations. At Bubbles Supply, we guarantee an exact fit for your system and offer same-day shipping on in-stock items, backed by our comprehensive 1-year warranty. The 1/2" male pipe thread connection ensures secure installation in your spa's circulation line. Verify your existing flow switch threading and electrical requirements before installation to ensure proper operation.

Exact part number

Q-12DS-C2-BEACH

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Also known as / Replaces

This part replaces or is interchangeable with:

  • 1/2 inch MPT flow switch
  • Harwil flow switch
  • pilot duty flow switch
  • Q-12DS-C2
  • Q12DSC2BEACH

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

Common symptoms this part fixes

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

  • Spa heater throwing OH (overheat) fault
  • HH error code on spa topside display
  • ICE error code or freeze protection triggering unexpectedly
  • Heater not firing despite water in system
  • Spa shutting down during normal operation
  • Control system not detecting water flow

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

Before you buy — quick checklist

  • Confirm your existing flow switch has 1/2" MPT (male pipe thread) connection — not FPT or barb
  • Verify your spa is a Beachcomber or confirm Q-12DS-C2 is the correct Harwil series for your control system
  • Check that your system requires a pilot duty rated flow switch, not a line voltage type
  • Test your current flow switch with a multimeter before ordering — confirm it's the switch, not a wiring or circulation pump issue
  • Inspect the existing flow switch paddle and chamber for scale buildup that may indicate a water chemistry problem needing correction

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

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

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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