If your machine does not heat, check the following:
Fill the water reservoir with non-purified water or softened (without calcium and magnesium) water. Distilled or purified water may not allow the machine to heat. if you experienced a lot of water on the counter and the aforementioned resolves the issue.
If your machine is still not heating, check the following:
Unplug the machine. Remove the water reservoir. Lay your machine upside down. Remove the 4 screws holding bottom cover. Depress the safety switch button (usually red in color). Examples are shown below.
If it depresses and you feel a click, then test the machine. Test and stay near machine to make sure the gauge does not exceed 1.3. If it does, then the pressurestat (Heating element controller) has a lot of limescale causing it to stick. The machine would need to be descaled and the pressurestat would need to be replaced.