> ## Content Index > Fetch the complete content index at: https://commodorehdcovers.com/llms.txt > Use this file to discover other available public pages before exploring further. # Best Hot Tub Temp Sensors and Heaters Compared - URL: https://commodorehdcovers.com/best-hot-tub-temp/ - Published: 2026-09-07T07:33:02.000Z - Updated: 2026-09-07T09:49:17.000Z - Description: A working temperature sensor is what stands between a warm soak and a flashing error code. Here is how seven picks compare for Balboa, Sundance and Jacuzzi setups, plus one heater and one floating thermometer. - Author: Aidyn Meadows - Tags: Computers & Networking, Hot Tubs, #Spa Parts The best hot tub temp sensor for most Balboa M7 owners is the Tobaiwind M7 replacement, because it ships as a two-pack with a 12-foot sensing wire that reaches almost any control board location. If your spa is a Sundance or Jacuzzi rather than a Balboa, the XMK 6600-166 is the pick, and it swaps the curled-finger connector cleanly. This roundup keeps the best hot tub temp advice tied to the exact board and connector you own, not to generic praise. In this guide 1. [Best hot tub temp picks at a glance](#best-hot-tub-temp-picks-at-a-glance) 2. [How I screened these picks](#how-i-screened-these-picks) 3. [1\. Tobaiwind Hot Tub Sensor for Balboa M7 — Best overall](#1-tobaiwind-hot-tub-sensor-for-balboa-m7-%E2%80%94-best-overall) 4. [2\. XMK Temperature Sensor 6600-166 — Best budget pick](#2-xmk-temperature-sensor-6600-166-%E2%80%94-best-budget-pick) 5. [3\. XMK Temperature Sensor 6600-167 — Runner-up](#3-xmk-temperature-sensor-6600-167-%E2%80%94-runner-up) 6. [4\. Blizonte Wireless Pool Thermometer — Best for beginners](#4-blizonte-wireless-pool-thermometer-%E2%80%94-best-for-beginners) 7. [5\. OCHIKI 6600-167 Temperature Sensor — Best for heavy use](#5-ochiki-6600-167-temperature-sensor-%E2%80%94-best-for-heavy-use) 8. [6\. JHAOHEATE 1500W Submersible Water Heater — Best premium](#6-jhaoheate-1500w-submersible-water-heater-%E2%80%94-best-premium) 9. [7\. Adabuing Balboa M7 Sensor Kit — Best for families](#7-adabuing-balboa-m7-sensor-kit-%E2%80%94-best-for-families) 10. [Which sensor fits which spa?](#which-sensor-fits-which-spa) 11. [What the error codes actually mean](#what-the-error-codes-actually-mean) 12. [Is a floating thermometer worth adding?](#is-a-floating-thermometer-worth-adding) 13. [How to swap a temp sensor without draining the tub](#how-to-swap-a-temp-sensor-without-draining-the-tub) 14. [What the listings do not tell you](#what-the-listings-do-not-tell-you) 15. [The verdict](#the-verdict) 16. [FAQ](#faq) ## Best hot tub temp picks at a glance | Pick | Fits | Connector / lead | Price | | ------------------------------------------------------------------------------------------------------------------- | ------------------------------- | ------------------------------------- | ---------------------------------------------------------------------- | | **Best overall**[Tobaiwind Balboa M7 Sensor](https://www.amazon.com/dp/B0CJXTT3PZ?tag=commodorehd-20) | Balboa M7 boards | 12 ft lead, 2-pack | [Check Price](https://www.amazon.com/dp/B0CJXTT3PZ?tag=commodorehd-20) | | **Best budget pick**[XMK 6600-166 Sensor](https://www.amazon.com/dp/B0C4PFZFXJ?tag=commodorehd-20) | Sundance & Jacuzzi J-300 series | Curled-finger, O-ring included | [Check Price](https://www.amazon.com/dp/B0C4PFZFXJ?tag=commodorehd-20) | | **Runner-up**[XMK 6600-167 Sensor](https://www.amazon.com/dp/B0C4PHHB6D?tag=commodorehd-20) | Sundance 880 & Jacuzzi J-400 | Box-end, O-ring included | [Check Price](https://www.amazon.com/dp/B0C4PHHB6D?tag=commodorehd-20) | | **Best for beginners**[Blizonte Wireless Pool Thermometer](https://www.amazon.com/dp/B0GX6QZB93?tag=commodorehd-20) | Any tub, cold plunge or pool | IP68 float, 3-year warranty | [Check Price](https://www.amazon.com/dp/B0GX6QZB93?tag=commodorehd-20) | | **Best for heavy use**[OCHIKI 6600-167 Sensor](https://www.amazon.com/dp/B0C9GJP4YH?tag=commodorehd-20) | Sundance 880 & Jacuzzi J-400 | Box-end, gold-plated contacts (claim) | [Check Price](https://www.amazon.com/dp/B0C9GJP4YH?tag=commodorehd-20) | | **Best premium**[JHAOHEATE 1500W Immersion Heater](https://www.amazon.com/dp/B0GZM7MS34?tag=commodorehd-20) | Inflatable tubs, plunges | 1500W, GFCI, LCD thermostat | [Check Price](https://www.amazon.com/dp/B0GZM7MS34?tag=commodorehd-20) | | **Best for families**[Adabuing Balboa M7 Sensor Kit](https://www.amazon.com/dp/B0CGDNSDMP?tag=commodorehd-20) | Balboa M7, VAL, LE systems | 24 in lead, 2-pack with hardware | [Check Price](https://www.amazon.com/dp/B0CGDNSDMP?tag=commodorehd-20) | ## How I screened these picks The best hot tub temp advice is worthless if the part does not fit the board. So the screen started with connectors, not brands. I lined up the published fitment lists and grouped the picks by control system: Balboa M7 on one side, Sundance and Jacuzzi on the other. Inside the Sundance and Jacuzzi group, I split by connector shape, because the 6600-166 curled-finger sensor and the 6600-167 box-end sensor look similar in a listing photo and are not interchangeable in a control pack. I then held two picks aside as different tools for a different problem: the Blizonte floating thermometer, which reads water temperature but does not talk to the spa board, and the JHAOHEATE immersion heater, which raises the temperature in tubs that have no built-in heater at all. Every remaining pick had to publish a model number, a fitment list, and a physical dimension or lead length. Anything vaguer than that was cut. ## 1\. Tobaiwind Hot Tub Sensor for Balboa M7 — Best overall **The Tobaiwind M7 sensor is the best hot tub temp pick because it targets the most common failure point on Balboa boards and ships as a redundant two-pack.** [![Tobaiwind Balboa M7 replacement temperature sensor on black lead — the exact part number that clears an HH or SN fault](https://m.media-amazon.com/images/I/31U5BoaMoaL._SL500_.jpg)](https://www.amazon.com/dp/B0CJXTT3PZ?tag=commodorehd-20) **Best for:** Balboa M7 owners who want a spare on the shelf **Skip it if:** your control pack is a Sundance or Jacuzzi board Balboa's M7 heater assembly is used across a huge slice of the North American spa market, and its temperature sensor is a known weak point. Tobaiwind's replacement is listed for parts 30344, 30042, 30382, 32016 and 53605, which covers the numbers most owners find printed on the failed sensor or on the schematic in the control-pack lid. The listing states 12 feet of sensing wire, which is long enough to route a new lead alongside the old one without cutting into the equipment bay. Count is two, so if one arrives damaged or you crimp a connector wrong, the swap is not blocked. Against the Adabuing M7 pick further down, this is the more expensive of the two Balboa options in the set, and the published lead length is longer. What it lacks are body dimensions beyond a placeholder figure, so measure your bay depth from the old sensor's grommet before ordering. **Pros:** - Fits the widest list of Balboa M7 part numbers here - Two-pack gives an immediate spare - 12-foot sensing wire routes past most control layouts - Aimed at the single most common M7 fault code **Cons:** - The most expensive pick in this set for a Balboa sensor - Body dimensions listed as a placeholder, not a real measurement - Only one seller stocks it [Check Price on Amazon](https://www.amazon.com/dp/B0CJXTT3PZ?tag=commodorehd-20) ## 2\. XMK Temperature Sensor 6600-166 — Best budget pick **The XMK 6600-166 is the cheapest of the seven and the correct part for curled-finger Sundance and Jacuzzi boards.** [![XMK 6600-166 curled-finger temperature sensor for Sundance and Jacuzzi spas with O-ring — the entry-level fix for a "- - - -" watchdog error](https://m.media-amazon.com/images/I/41mPgHENiJL._SL500_.jpg)](https://www.amazon.com/dp/B0C4PFZFXJ?tag=commodorehd-20) **Best for:** Sundance and Jacuzzi tubs using the curled-finger 6600-166 **Skip it if:** your old sensor has box-end connectors If your spa is a Jacuzzi J-300 through J-365, or a Sundance 680 Series, Peyton, Denali, Tacoma, Dover, or a Sweetwater from 1998 to 2004, this is the sensor the listing calls out by name. The connectors are the curled-finger type that plug directly onto the pins on the Sundance and Jacuzzi board, and the 6540-228 O-ring ships with the part, which matters because a dry O-ring is what leaks when you refill. Dimensions are given as 1.6 x 6.1 x 4 inches, which is the packaging box rather than the sensor body itself, so plan the routing from the old lead's length, not the packaging. The listing calls the sensor a fix for the "- - - -" watchdog error, which is the display Sundance and Jacuzzi packs show when they cannot read a valid temperature. That is the exact fault this pick solves, and nothing more ambitious. **Pros:** - Cheapest option in this set - Correct connector shape for J-300 and 680 Series boards - O-ring included - Long fitment list on Sundance side **Cons:** - Not compatible with 6600-167 box-end boards - Sensor body dimensions not published - Only one seller lists it [Check Price on Amazon](https://www.amazon.com/dp/B0C4PFZFXJ?tag=commodorehd-20) ## 3\. XMK Temperature Sensor 6600-167 — Runner-up **The 6600-167 sibling is the runner-up because it covers the other half of the Sundance and Jacuzzi world: the box-end 880 Series and J-400 boards.** [![XMK 6600-167 box-end temperature sensor for Sundance 880 and Jacuzzi J-400 — the swap for "0000", "OH" and "ICE" errors](https://m.media-amazon.com/images/I/41idbVoFuLL._SL500_.jpg)](https://www.amazon.com/dp/B0C4PHHB6D?tag=commodorehd-20) **Best for:** Sundance 880 and Jacuzzi J-400 owners with a 6600-167 board **Skip it if:** you own a J-300 curled-finger model Owners of a 2005-and-newer Sundance 880 System, a 2012-and-newer Aspen, a Jacuzzi J-300 LCD Series from 2002, or any J-400 from 2006 to 2009 need the 6600-167 with box-end connectors, not the 6600-166\. Same brand, same second-cheapest position, same 6540-228 O-ring. The listing calls out four separate error codes it is meant to clear: "- - - -", "0000", "OH" and "ICE", which are the four ways a Sundance or Jacuzzi board tells you it has lost confidence in the reading. Against the OCHIKI 6600-167 further down, this pick is cheaper and does not claim gold plating on the contacts. If both packs are on the shelf, this is the value option and OCHIKI is the upgrade. Against the curled-finger 6600-166, only the connector shape differs, so match the part to the pins on your board rather than to the model year of the tub. **Pros:** - Correct connector for 880 Series and J-400 boards - Second-cheapest pick in the set - O-ring included - Listed as a fix for four separate Sundance and Jacuzzi codes **Cons:** - Wrong shape for curled-finger boards - No gold plating on the contacts, unlike the OCHIKI equivalent - Sensor body dimensions not published [Check Price on Amazon](https://www.amazon.com/dp/B0C4PHHB6D?tag=commodorehd-20) ## 4\. Blizonte Wireless Pool Thermometer — Best for beginners **Blizonte's floating thermometer is the pick when you want a second opinion on water temperature without opening the equipment bay.** [![Blizonte wireless floating pool thermometer with indoor receiver showing water and room temperature — a check on what the spa board thinks the water is doing](https://m.media-amazon.com/images/I/41a+7mQ0lCL._SL500_.jpg)](https://www.amazon.com/dp/B0GX6QZB93?tag=commodorehd-20) **Best for:** anyone who wants a floating readout without wiring anything **Skip it if:** you need the tub itself to read the correct temperature This is the only pick in the set that does not require a screwdriver. The transmitter floats in the spa, the receiver sits indoors, and the listing states an IP68 rating on the submersible transmitter and a data refresh every 57 seconds. It records 24 hours of highs and lows, which is useful when you suspect the tub is overshooting overnight or during a heater cycle. A three-year warranty is published, which is the longest of any pick here. Blizonte says the receiver shows a "COLD", "COMFORT" or "HOT" label, which is a preset comfort algorithm rather than a measurement. Treat those labels as decoration and read the number. Important limit: this thermometer does not fix a bad spa sensor. If your board is showing an error code, a floating readout tells you what the water is actually doing while you order the correct wired sensor. It is a diagnostic tool, not a repair. **Pros:** - No wiring or spa access required - IP68 waterproof rating on the transmitter - 24-hour min and max recording - Three-year warranty, the longest in this set - Dual USB or AAA power **Cons:** - Does nothing to clear a spa error code - Batteries not included - Comfort label is a preset, not a measurement [Check Price on Amazon](https://www.amazon.com/dp/B0GX6QZB93?tag=commodorehd-20) ## 5\. OCHIKI 6600-167 Temperature Sensor — Best for heavy use **OCHIKI's 6600-167 replaces the same box-end Sundance and Jacuzzi part as the XMK runner-up, but the listing claims gold-plated contacts and a threaded O-ring seal.** [![OCHIKI 6600-167 replacement temperature sensor with gold-plated terminal — an upgraded contact on a familiar Sundance and Jacuzzi part number](https://m.media-amazon.com/images/I/41Vdq8LRRYL._SL500_.jpg)](https://www.amazon.com/dp/B0C9GJP4YH?tag=commodorehd-20) **Best for:** Sundance owners who want gold-plated contacts on a 6600-167 swap **Skip it if:** you already own the XMK equivalent and it is working OCHIKI covers the same fitment ground as the XMK 6600-167: Sundance Aspen from 2012, 850 Systems from 1997 to 2005, 880 Systems from 2005 on, and Jacuzzi J-300 LCD, J-350, J-360, J-380, J-355, J-365, J-375, J-385 and J-400 models. The listing adds two claims XMK does not: gold plating at the terminal end, which OCHIKI says improves conductivity and accuracy, and a threaded design on the connector with a 6540-228 O-ring for sealing. Both are manufacturer claims rather than measured facts, so weigh them as marketing until your own tub proves otherwise. Where this pick loses to the XMK sibling is price position: it is the third-cheapest and XMK is the second-cheapest, for the same part number. Where it wins is that heavy-use tubs cycle their sensors through more thermal load, and a listing that at least talks about corrosion at the terminal is more reassuring than one that does not. It is the slowest seller of the three Sundance and Jacuzzi picks. **Pros:** - Same broad fitment list as the XMK 6600-167 - Gold-plated contacts (manufacturer claim) - Threaded connector with O-ring for sealing - Also replaces 6600-182, 6600-138 and 6600-105 **Cons:** - More expensive than the XMK equivalent - Body dimensions not published - The slowest seller of the three Sundance and Jacuzzi picks [Check Price on Amazon](https://www.amazon.com/dp/B0C9GJP4YH?tag=commodorehd-20) ## 6\. JHAOHEATE 1500W Submersible Water Heater — Best premium **The JHAOHEATE immersion heater is the outlier: it does not fit a hard-shell spa, but it turns an inflatable tub, cold plunge or stock tank into something you can actually soak in.** [![JHAOHEATE 1500W submersible immersion heater with LCD thermostat and GFCI plug — the heater for tubs that do not have one built in](https://m.media-amazon.com/images/I/51GP-sBenEL._SL500_.jpg)](https://www.amazon.com/dp/B0GZM7MS34?tag=commodorehd-20) **Best for:** inflatable tubs, cold plunges and stock tanks with no built-in heater **Skip it if:** you have a hard-shell spa with its own heater and control pack Rated at 1500W on a 120V circuit, this is a 15-inch stainless rod that hangs into the water with a thermostat probe alongside it. JHAOHEATE says the LCD holds ±0.1°C accuracy and that the heater is built from food-grade 316 stainless steel. A GFCI plug is fitted in-line to cut power on a leakage fault, which is the electrical protection you want when the heater and the bather share a water bath. A support ring keeps the rod off the wall of an inflatable tub, so the vinyl does not melt. This is the most expensive pick in the set and it is the slowest seller by a wide margin, which reflects how narrow the use case is. If your spa has a working heater and a working control pack, you do not need this. If your "hot tub" is an inflatable Intex or a converted stock tank, this pick is why the roundup includes it at all. **Pros:** - 1500W heat output on a standard 120V outlet - GFCI leakage protection in-line - LCD thermostat with ±0.1°C target accuracy (claim) - 316 stainless steel body - Support ring keeps the rod off inflatable walls **Cons:** - Most expensive pick in this set - Not a fix for a hard-shell spa with a built-in heater - The slowest seller of the seven [Check Price on Amazon](https://www.amazon.com/dp/B0GZM7MS34?tag=commodorehd-20) ## 7\. Adabuing Balboa M7 Sensor Kit — Best for families **Adabuing's kit is the family-shed pick because it ships two sensors, a plastic compression nut, a washer and an O-ring, so a household with more than one spa or a neighbour's tub to fix is covered.** [![Adabuing Balboa M7 sensor two-pack with 24-inch lead and hardware — a full kit for households with more than one hot tub to look after](https://m.media-amazon.com/images/I/31IkwoxYJcL._SL500_.jpg)](https://www.amazon.com/dp/B0CGDNSDMP?tag=commodorehd-20) **Best for:** Balboa M7 households that want a 24-inch lead and a spare in the kit **Skip it if:** you need a shorter lead than 24 inches Same Balboa fitment as the Tobaiwind pick above: parts 53605, 32016, 30042, 30344 and 30382, plus VAL and LE systems on the same M7 platform. Where it differs is the lead length. Adabuing publishes a 24-inch Temp/Hi Limit lead and a 1/4-inch diameter probe, which is short next to Tobaiwind's 12-foot sensing wire. If your control pack sits close to the heater tube, 24 inches is plenty and the shorter lead is tidier. If your bay is deep or the wire has to route around a pump, the Tobaiwind is the better fit. Weight is listed at 2.72 oz and the sensor count is two per kit. The listing calls out "HH" and "SN" error codes as the faults it clears, which are the Balboa versions of a shorted sensor and an open sensor respectively. It is the second-most expensive Balboa option here, and the trade-off against Tobaiwind is short lead versus long lead in a similar two-pack. **Pros:** - Full kit: sensors, nut, washer, O-ring - 24-inch lead is tidy in a shallow equipment bay - Two-pack for a spare - Listed as a fix for HH and SN codes - Weight and dimensions actually published **Cons:** - 24-inch lead is short if the bay is deep - Premium price band on a Balboa sensor - Sales rank is the lowest of the M7 pair [Check Price on Amazon](https://www.amazon.com/dp/B0CGDNSDMP?tag=commodorehd-20) ## Which sensor fits which spa? The temperature sensor on a hot tub is a spa-specific part. Ordering the right one is a matter of three questions, in order. 1. **What is the brand of the control pack?** Balboa is the M7 world. Sundance and Jacuzzi share the 6600-series world. Nothing crosses over. 2. **What connector is on the wire?** Sundance and Jacuzzi split into curled-finger (6600-166) and box-end (6600-167). Look at the plug on the failed sensor, not the model year of the tub. 3. **What lead length do you need?** Measure from the heater's grommet or the sensor well to the terminal on the board, and add a foot for routing. The best hot tub temp match happens when all three answers line up. A curled-finger 6600-166 will not plug onto a box-end board even if the tub is the right brand. A Balboa M7 sensor will not read on a Sundance pack even if the physical connector looks similar. And a 24-inch lead will not reach a control pack sitting three feet from the heater tube. ## What the error codes actually mean Spa boards do not throw random text. Each error code maps to one thing the sensor is telling the board. - **"- - - -" or "0000"**: watchdog fault. The board cannot read a valid signal from the sensor at all. Usually a cut wire, a corroded connector, or a dead sensor element. - **"HH"**: high-high. The board sees a temperature so high it must be a fault, or it sees a shorted sensor reporting infinity. - **"SN"**: sensor open. The board sees no continuity, which is what a snapped internal wire looks like. - **"OH"**: overheat. The high-limit sensor has tripped. Could be a real overheat, or a stuck sensor reading falsely high. - **"ICE"**: freeze warning. The board thinks the water is at or below freezing. On a stuck sensor, this shows in summer. Each of the seven picks except the Blizonte and the JHAOHEATE is aimed at clearing one or more of these. Match the code to the sensor, not the sensor to the tub's badge. ## Is a floating thermometer worth adding? Yes, and for a specific reason. When a spa board and a floating thermometer disagree, the disagreement is the diagnosis. If the spa says 104°F and the Blizonte says 96°F, the spa sensor is drifting high and the heater is shutting off early. If the spa says 90°F and the Blizonte says 104°F, the spa sensor is drifting low and the heater is chasing a target it has already passed. Either way you have a real number to work from before you order a wired replacement. A floating thermometer is not a fix for an error code and it is not a substitute for a working sensor. It is a second opinion. In a household that suspects a slow drift rather than a sudden fault, that second opinion is worth having on the water. ## How to swap a temp sensor without draining the tub The trick with most spa temperature sensors is that they thread into a sensor well or clip into the heater tube from the equipment side, not the water side. So a full drain is often unnecessary. 1. Kill power at the breaker, not just at the topside panel. 2. Open the equipment bay door and find the failed sensor's lead back to the control board. 3. Disconnect the old lead at the board. 4. Cut the old lead a foot from the sensor and tape the new sensor wire to the old one. 5. Pull the old wire back through the bay, dragging the new wire into position. 6. Fit the new sensor into the well or clip, hand-tight on the compression nut, with the supplied O-ring seated dry. 7. Plug the new lead into the board and restore power. Two safety points. First, the GFCI on a hard-shell spa should trip on any live wiring work; if it does not, the GFCI is the next fault to chase. Second, dry-fit the O-ring, then wet it lightly on refill. A greased O-ring in this application swells. ## What the listings do not tell you Three things the product pages will not admit. - **Sensor packs and O-rings age together.** A new sensor with the original 20-year-old O-ring will leak. Every sensor pick here except the Tobaiwind explicitly ships a new O-ring; on the Tobaiwind, budget for a 6540-228 alongside. - **A "compatible with" list is not a promise.** The 6600-167 fits Sundance 880 and Jacuzzi J-400, but a rev change on a control pack can quiet-swap a connector. Photograph your failed sensor before ordering. - **Two-packs are not a discount, they are a redundancy.** The Balboa picks ship as pairs because M7 sensors are the part most likely to fail again in the same season. Keep the spare in the equipment bay, taped to the lid. ## The verdict If your spa is Balboa M7 and your control pack sits away from the heater tube, the Tobaiwind M7 sensor is the pick. The 12-foot lead reaches, the two-pack gives you a spare, and the fitment list covers every Balboa part number a household is likely to find on the failed part. If the bay is shallow and 24 inches of lead is enough, the Adabuing kit is the tidier install with more hardware in the box. If your spa is Sundance or Jacuzzi, ignore both Balboa picks and match the connector. Curled-finger boards take the XMK 6600-166\. Box-end boards take the XMK 6600-167 for the cheaper of two options, or the OCHIKI 6600-167 if the listing's gold-plating claim is worth the step up. The Blizonte thermometer belongs alongside a wired repair, not instead of one. And the JHAOHEATE immersion heater only earns its place if your "hot tub" is inflatable or a converted plunge with no heater of its own. The best hot tub temp fix is always the one that matches the connector on your board. ## FAQ ### What is the best hot tub temp sensor for a Balboa M7 system? The best hot tub temp sensor for a Balboa M7 system in this set is the Tobaiwind M7 replacement, which is listed for part numbers 30344, 30042, 30382, 32016 and 53605, with a 12-foot sensing wire and a two-pack. The Adabuing kit is the runner-up if a 24-inch lead is enough and you want the compression nut, washer and O-ring in the box. ### Is a wired sensor swap worth it over calling a spa technician? A wired sensor swap is worth it for owners comfortable killing power at the breaker and pulling a wire through an equipment bay. The tape-and-drag method in this guide avoids draining the tub, and every wired pick here ships with the connector already fitted. A technician's call-out fee usually exceeds the cost of the part several times over, so the maths favours the swap. ### What is the difference between the 6600-166 and 6600-167 sensors? The difference between the 6600-166 and 6600-167 sensors is the connector shape at the board end. The 6600-166 uses curled-finger connectors and fits Sundance 680 Series, Peyton, Denali and Jacuzzi J-300 through J-365 tubs. The 6600-167 uses box-end connectors and fits Sundance 880 Systems, Aspen, and Jacuzzi J-400 models. They are not interchangeable. ### Tobaiwind or Adabuing for a Balboa M7 replacement? Tobaiwind or Adabuing depends on lead length. Tobaiwind publishes a 12-foot sensing wire, which suits deep equipment bays or awkward routing paths around pumps and unions. Adabuing publishes a 24-inch lead with a full hardware kit, which suits shallow bays where a long wire coils awkwardly. Both are Balboa M7 two-packs. Measure your bay first, then decide. ### What is the biggest mistake people make ordering a spa temp sensor? The biggest mistake people make is ordering by the badge on the tub instead of the connector on the wire. A 2010 Jacuzzi could be a J-365 (curled-finger 6600-166) or a J-400 (box-end 6600-167), and the wrong pick will not plug in. Pull the failed sensor first, photograph the connector, and match the picture to the fitment list. Before you click on the pick that matches your tub, pull the failed sensor out of the equipment bay and photograph the connector end. Compare that photograph to the images on the Tobaiwind, XMK 6600-166, XMK 6600-167 or Adabuing pages before you commit. On a hard-shell spa, the correct sensor is a fifteen-minute job with a screwdriver and a phone torch. The wrong sensor is a return label and another week of cold water. That single photograph is the difference between the best hot tub temp fix and a second order. *Last updated: September 21, 2026\. Product availability re-checked.* *This page contains affiliate links. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.*