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3 Pin MTA Flow Switch Q12DSCSLA - Bubbles Supply

3 Pin MTA Flow Switch Q12DSCSLA

Part #: Q12DSCSLA

$201.73
In stock — ships today
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1-year warrantySame-day ship before 3pm CTPerfect Fit Guarantee30-day returns

About this flow switch

The Harwil Q12DSCSLA is a 3-pin MTA flow switch engineered specifically for LA Spas systems. This precision sensor monitors water flow through your spa's plumbing system and communicates with the control board to prevent dry-fire conditions that can damage your heater. Factory calibrated for LA Spas specifications, this 1/2" MPT threaded flow switch ensures reliable operation and proper system protection.

At Bubbles Supply, this genuine Harwil flow switch comes with our exact fit guarantee, ships same-day from our Canadian warehouse, and includes a full 1-year warranty for complete peace of mind. The 3-pin MTA connector provides secure electrical connection to your spa's control system. Professional installation recommended to ensure proper threading and optimal sensor positioning within your spa's circulation system.

Exact part number

Q12DSCSLA

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • 3-pin MTA flow switch
  • Harwil flow switch
  • LA Spas flow switch
  • Q12DSCSLA flow switch

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 displays HH, ICE, or OH error codes
  • Heater not activating despite adequate water level
  • Spa goes into protection mode and shuts down
  • Control board not detecting water flow
  • Spa repeatedly throwing flow-related fault codes
  • Heater cycling off prematurely during normal operation

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

Before you buy — quick checklist

  • Confirm your spa is an LA Spas brand unit — this switch is factory-calibrated for LA Spas systems
  • Verify your existing flow switch uses a 3-pin MTA connector before ordering
  • Check that your plumbing tee accepts a 1/2" MPT threaded fitting
  • Inspect the wiring harness connector on your control board side for damage before replacing the switch
  • Rule out an air lock or low water level as the root cause of flow faults before replacing the sensor

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

  • Harwil Q12DSCSLA flow switch
  • 3-pin MTA connector pre-wired
  • Thread sealant not included — use PTFE tape on 1/2" MPT threads

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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