For Yijianeng solar water heater, my controller does not display the temperature, and the water level is only up and down, with a blank in the middle. Can Jianchang, Huludao, Liaoning be repaired?

Obviously, the sensor in your water tank is broken. Call after-sales service. If there is no after-sales service, you can only go up and find the thinnest signal wire, cut it to see how many cores there are, and then buy one from the local solar accessories and replace it. The cost is about 25-60 yuan.