This Product Has Been Discontinued
The Hills Esteem Blue Tank Sensor (2007–2010) has been discontinued and is no longer available for purchase.
This page has been retained to help customers identify this sensor and to provide technical reference information.
Need a Replacement?
There is no direct replacement available for this tank sensor.
Email sales@solarhotwaterparts.com.au with a photo of your controller and your system details, and we will let you know what options exist for your system.
Technical Reference
Before replacing a tank sensor, check the sensor port or immersion sleeve for moisture. If moisture is present, the port or sleeve needs replacing as well. This is common in older stainless steel tanks, where the original sensor port develops pin holes because it is the weaker metal.
Sensors are not designed to sit in water, and moisture gives them an inaccurate reading. If you find moisture, check the roof sensor and the circulating pump before ordering anything. A pump motor that runs is not proof that water is circulating as it should.
Tank sensors must not be used as roof sensors. Tank sensors are normally PVC cable rated to around 90°C, whereas roof sensors are high temperature silicone rated two to three times higher.
Not all sensors are the same. Manufacturers changed controllers several times over the years, and the thermistor inside each sensor gives a different resistance curve, which the controller uses to calculate the differentials that operate the circulating pump.
The image above shows the original sensor type for reference.