Jandy | 7790 | Temperature Sensor Kit, Air, Water or Solar, 15 ft Cord, Fits AquaLink RS, PDA and Z4

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 and ships with its sealing O-ring.

One Part, Three Positions

The same sensor serves as the air, water or solar probe. The job is set by where you mount it, not by a different part number. If you are replacing two sensors on one system, order this part twice.

• Water: drill a 3/8 in hole in the pipe between the pump and 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 next to the solar collectors.

All three connect to the green 10 pin terminal bar on the power center board.

Compatible Systems

• Jandy AquaLink RS, including 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 (direct replacement)

Key Features

• Genuine Jandy OEM: factory calibrated 10K ohm thermistor, not a generic substitute.
• 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 with no extra parts.
• Direct Polaris S20 replacement.

Specifications

• Part Number: 7790
• UPC: 052337003278
• Type: Temperature sensor kit, air, water or solar
• Thermistor: 10K ohm NTC
• Cord Length: 15 ft, two conductor
• Color: Gray
• Probe Size: 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

Frequently Asked Questions

Is this the air sensor or the water sensor?

Both. It is the same part in either position. Where you mount it decides whether it reads air, water or solar. Order one per position you are replacing.

Can I extend the cord if 15 ft will not reach?

No. Jandy says to cut and discard excess rather than splice or extend. Splicing changes the resistance the controller reads and skews the temperature. There is no OEM extension.

How do I know the sensor has failed?

A reading stuck on one value, an impossible reading, dashes on the display 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 probes sold as 7790 replacements. This is the genuine Jandy part with the factory thermistor calibration your controller expects.

How is it installed in the pipe?

Drill a 3/8 in hole between the pump and filter, seat the O-ring against the pipe wall and hold it with a stainless clamp. Do not overtighten, excess clamp pressure cracks the probe boss.

Do I need a professional?

The sensor is low voltage and within reach of a capable 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.

What is the warranty?

Standard Jandy manufacturer warranty. Keep your 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.