Jandy 7790 Temperature Sensor Kit — Air, Water or Solar, 15 ft Cord, Gray — AquaLink RS, PDA & Z4 — Genuine OEM
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The Jandy 7790 Temperature Sensor Kit is the genuine OEM temperature probe used across Jandy, Zodiac and Polaris pool automation. It is a sealed 10K ohm thermistor on a 15 ft two-conductor cord, supplied with its sealing O-ring.
One Part, Three Jobs
This is the same sensor whether your system needs an air, water or solar reading — the role is decided by where you mount it, not by a different part number. If you are replacing two sensors on the same system, you are ordering this SKU twice.
- Water: drill a 3/8 in hole in the pipe between the pump and the filter, seat the O-ring and secure with a stainless pipe clamp.
- Air: mount outside the power center in shade, away from heat sources and power wiring.
- Solar: mount adjacent to the solar collectors.
All three land on the green 10-pin terminal bar on the power center board.
Compatible Systems
- Jandy AquaLink RS — RS4, RS6, RS8 and variants
- Jandy PDA
- AquaLink Z4
- Jandy Solar Control System
- Jandy power center PCB
- Polaris EOS controller and Sol 1000
- Polaris S20 — this is the direct replacement
Key Features
- Genuine Jandy OEM: factory-calibrated 10K ohm thermistor, not a generic substitute.
- Serves air, water or solar: one part number covers all three sensor positions.
- 15 ft cord: reaches from the power center to pad plumbing or an outdoor air position.
- O-ring included: seals into a 3/8 in hole without additional parts.
- Direct Polaris S20 replacement: a useful route when the S20 is unavailable.
Specifications
- Part Number: 7790
- Type: Temperature sensor kit — air, water or solar
- Thermistor: 10K ohm NTC
- Cord Length: 15 ft, two conductor
- Colour: Gray
- Probe Dimensions: 15 in L x 0.2 in W x 0.2 in D
- Mounting Hole: 3/8 in
- Includes: Sensor and O-ring
- Alternate Part Numbers: 6848, JDY3015097, 59-295-1102, JDY-301-2839
- Brand: Jandy / Zodiac (Genuine OEM)
Frequently Asked Questions
Is this the air sensor or the water sensor?
Both. It is the same part in either position — what makes it an air, water or solar sensor is where you mount it. If you are replacing more than one on the same system, order this part more than once.
Can I extend the cord if 15 ft will not reach?
No. Jandy's instructions say to cut and discard any excess rather than splice or extend. Splicing changes the resistance the controller measures and will skew your temperature readings. There is no OEM extension for this sensor.
How do I know the sensor has failed?
Common signs are a temperature reading stuck at one value, a wildly implausible reading, a display showing dashes in place of a temperature, or a heater or solar valve that will not call because the controller thinks the target is already met.
Will it work with my Polaris S20?
Yes. The 7790 is the published direct replacement for the Polaris S20 sensor.
Is this the same as the cheaper sensors sold online?
No. There is a large aftermarket in generic "replaces 7790" probes. This listing is the genuine Jandy OEM part with the factory thermistor calibration your controller expects.
How is it installed in the pipe?
A 3/8 in hole is drilled in the pipe between the pump and filter, the O-ring seats against the pipe wall and a stainless clamp holds it. Do not overtighten — excessive clamp pressure cracks the probe boss.
Frequently asked questions
What is the part number for this sensor?
Jandy lists this sensor under part number 7790. Quote 7790 when you cross-reference it against your equipment manual, an existing part, or a parts diagram, so you are comparing the same revision.
How do I confirm this fits my equipment?
Match the part number on the component you are replacing, or look it up in the parts list for your Jandy control system. If your model or serial number is not named on this page, send it to us before you order and we will confirm the fit.
Does this need a professional to fit?
The sensor itself is low voltage and within reach of a competent owner, but it lands inside a power center that also carries line voltage. Cut power at the breaker before opening the enclosure, and have a licensed professional handle anything on the supply side.
Is there a warranty on this part?
It carries the standard Jandy manufacturer warranty. The terms are set by Jandy. Keep the receipt and packaging until you have confirmed correct operation.
California Proposition 65 Warning: This product can expose you to chemicals known to the State of California to cause cancer and reproductive harm. For more information go to www.P65Warnings.ca.gov.