The indication of the E19 Error code on the main screen of your Siemens appliance is the signal that not everything is good with the heat-exchanger, which is responsible for proper heating of the water with less power needed for the process.
The Error points on the issues with the heat exchanger itself or with one of its part called the drain valve. Anyway, this is a rare and easily deciphered code, which can be reset by replacing the damaged part.
Heat Exchanging technology is an essential part of all the modern Siemens dishwashers. It makes the process more eco-friendly, by consuming less energy. The use of this technology also reduces the risk of thermal shock.
How to fix the E19 Error?
To start checking the exchanger and the valve, switch off and unplug the device from the main power. The next step will be to drain all the water out of the machine. Make sure there is no water left and only then you can start disassembling the heat-exchanger.
When you get to it, check the exchanger and the valve for any visible signs of damage and replace the needed parts, carefully installing them as they were before.