Aestiva Tank Sensor
Image of the solar hot water controller above is included to assist you find the appropriate product for your system (controller is not included in the sale price).
If you are just replacing the tank sensor on your system, we recommend you check the sensor port or immersion sleeve for moisture. If there is moisture, the sensor port or immersion sleeve will need to be replaced. This is mostly a problem in the older stainless steel hot water tanks. The original sensor port develops pin holes because it is the weaker metal.
Sensors are not designed to be installed in water and the moisture gives them an inaccurate reading. If you find moisture, check the roof sensor and the circulation pump first before ordering a tank sensor. Just because the pump motor is running does not mean it is circulating water as it should. With some models of solar hot water systems, your best option may be replacing everything at once with a complete pump station. Please contact us if you have questions about this before you purchase this item.
It is important that tank sensors are not used as roof sensors. Tank sensors are normally made from PVC cable and not high temperature silicone cable. Tank sensors are generally only rated to 90 degrees, whereas roof sensors can be rated two to three times higher.
Not all sensors are the same. This is a common mistake because over the years some manufacturers changed controllers multiple times. The thermistor inside the sensor gives different resistance levels with temperature change and the controller uses the reading to calculate the differentials required to operate the circulating pump.
There are many different types of controllers that use different types of sensors. If you are unsure, email us a photo of your controller and we can guide you to the correct sensor.