Errors E1, E2 and E5: abnormal temperature around the heating element

What it means

As well as the heat pump, these water heaters have a back-up electric heating element, with sensors that monitor the temperature around it. If the temperature rises too quickly or goes over the limit, the water heater stops heating and shows a code.

According to the manufacturer, E1 means heating with no water in the tank; E2, water temperature too high; and E5, an excessive temperature difference between the sensors around the heating element.

With very hard water, limescale builds up around the heating element. The heat doesn't spread evenly, so that area heats up very quickly and one of these warnings usually comes up.

Most likely causes

1. Limescale build-up around the heating element. This is the most common cause with Mallorca's water.
2. Lack of water in the tank, in the case of E1: a water supply cut-off or a closed inlet valve.
3. A temperature sensor that isn't reading correctly.
4. The heating element or its controls.

What you can check yourself

Without tools and without opening the unit.

1. Check that water is reaching the water heater: turn on a cold tap and check the water heater's inlet valve. With the handle in line with the pipe, it's open.
2. Switch the water heater off and back on again after a while, as the manufacturer advises.
3. Be careful with hot water from the taps in the meantime: it may come out hotter than normal.
4. Watch whether the warning comes back over the next few days.

If the warning comes back after switching it off and on, don't keep trying: book an engineer. Most likely the limescale needs removing or the heating element and sensors need checking, and that's a job for an engineer. And if the water comes out very hot or you see steam at the taps, switch the water heater off.