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275-3183-00

48" Mechanical Thermostat 275-3183-00

Part #: 275-3183-00

$36.94
In stock — ships today
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1-year warrantySame-day ship before 3pm CTPerfect Fit Guarantee30-day returns

About this sensor

This 48" mechanical thermostat (275-3183-00) is a genuine Robertshaw replacement sensor designed for spa and hot tub temperature control systems. The unit features a 48-inch capillary tube with a 5/16-inch sensing bulb, providing precise mechanical temperature regulation for your spa's heating system. This OEM-quality thermostat effectively resolves common spa issues including overheating (OH), freeze protection (ICE), and heater operation problems (HH).

Engineered to Robertshaw's exacting standards, this mechanical thermostat delivers reliable temperature sensing and control without requiring electrical connections. At Bubbles Supply, we guarantee an exact fit for your spa with same-day shipping on in-stock items, backed by our comprehensive 1-year warranty. The 48-inch capillary length provides flexible installation options while the mechanical design ensures dependable operation even during power interruptions. Verify your existing thermostat's capillary length and bulb diameter before ordering to ensure proper fitment.

Exact part number

275-3183-00

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Also known as / Replaces

This part replaces or is interchangeable with:

  • bulb thermostat
  • capillary thermostat
  • capillary tube thermostat
  • mechanical spa thermostat

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 overheating (OH fault) with no obvious heater failure
  • Spa not reaching or holding set temperature
  • Freeze protection (ICE) not activating or activating incorrectly
  • Heater running continuously and won't shut off
  • Spa displaying HH (heater high-limit) fault codes
  • Erratic temperature swings despite correct thermostat settings

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

Before you buy — quick checklist

  • Measure your existing capillary tube length — this unit is 48 inches; shorter or longer capillary won't route correctly
  • Confirm your existing sensing bulb diameter is 5/16 inch before ordering
  • Verify this is a mechanical thermostat application — do not substitute for a digital or electronic sensor without confirming compatibility
  • Identify whether the fault is in the thermostat itself or in a separate high-limit sensor, as these are different components
  • Check that mounting provisions in your spa's equipment bay accept the existing thermostat bracket style

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

  • Robertshaw mechanical thermostat
  • 48-inch capillary tube with 5/16-inch sensing bulb

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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