🚀 New launch promo — 10% off orders over $300. Use code LAUNCH10
Bubbles Supply
Not sure which part you need? Upload a photo and we'll find it. →
IN.YJ Hi-Limit Sensor Heat Recovery 9920-401397 - Bubbles Supply

IN.YJ Hi-Limit Sensor Heat Recovery 9920-401397

Part #: 9920-401397

$134.92
In stock — ships today
Qty
🔒 Secure checkout↩️ 30-day returns✅ 1-year warranty
Add to B2B order list

Not sure this fits?

Send us a photo of your old part — we'll confirm the right replacement before you order.

Upload a Photo
1-year warrantySame-day ship before 3pm CTPerfect Fit Guarantee30-day returns

About this heater

The IN.YJ Hi-Limit Sensor Heat Recovery 9920-401397 is a genuine Gecko Alliance temperature safety sensor designed for spas equipped with Gecko control systems. This critical safety component features a 48-inch cable length and 3/8-inch sensing bulb, providing reliable over-temperature protection to prevent dangerous heating conditions in your spa.

Built to OEM specifications, this hi-limit sensor ensures your spa's heating system operates safely within proper temperature ranges. At Bubbles Supply, we guarantee an exact fit for your Gecko system with same-day shipping and back every sensor with our comprehensive 1-year warranty. This sensor mounts in your spa's plumbing system near the heating element—verify your existing sensor's cable length and bulb diameter match these specifications before installation to ensure proper fit and optimal safety performance.

Exact part number

9920-401397

Save this for ordering or warranty claims

Also known as / Replaces

This part replaces or is interchangeable with:

  • heat recovery sensor
  • Hi-limit sensor
  • high-limit sensor
  • overheat sensor
  • spa temperature safety sensor

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 shuts down with hi-limit fault code
  • Heater trips off prematurely before reaching set temperature
  • Spa displays OH or overheat error on control panel
  • Spa will not heat at all despite no other obvious faults
  • Inconsistent or erratic temperature readings on topside display

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

Before you buy — quick checklist

  • Confirm your spa runs a Gecko IN.YJ control system before ordering
  • Measure your existing sensor's cable length — this unit is 48 inches, ensure it reaches your mounting location
  • Verify your existing sensor's bulb diameter is 3/8 inch to confirm a physical fit in the sensor well or plumbing port
  • Check whether your spa throws a specific hi-limit fault code (not a flow or pressure fault) to confirm the sensor is the failed component
  • Inspect the sensor well or port for corrosion or debris before installing the new 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

  • IN.YJ Hi-Limit Sensor (9920-401397)
  • 48-inch sensor cable with connector
  • Sensing bulb (3/8-inch diameter)

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.

🔒 Secure checkout · SSL encrypted·🇺🇸🇨🇦 Serving the US and Canada·↩️ 30-day hassle-free returns·📦 Same-day fulfillment