Denys Danyliuk Key Takeaways
- E01 on a Bosch dishwasher means the heating element or its circuit has failed.
- The machine can still run, but dishes are not properly sanitized, so avoid it for baby bottles.
- The three causes are a burned-out element, a failed board relay and damaged wiring.
- A power reset rarely clears E01, and a repeat code after reset means a repair is needed.
- Check the water heater, run the tap hot and reset once before you book.
The Bottom Line
E01 is a heating fault that will not clear itself. Hand-wash the critical items, run the three safe checks once and book a diagnostic before the cold-water cycles pile up.
A Bosch dishwasher E01 error means the machine cannot heat its wash water, because the heating element or the circuit that feeds it has failed. The code page for the Bosch dishwasher E01 code rates it high severity and names three suspects: a burned-out element, a failed relay on the control board and damaged wiring between the two. The machine may keep running with the fault, which is why E01 is easy to ignore for weeks while the dishes come out cold and greasy.
| What you notice | What it points to | What to do first |
|---|---|---|
| Dishes come out greasy and cold | Wash water never reaches the program temperature | Run the kitchen tap hot before you start |
| Water in the tub stays cold through the cycle | The heating element is not producing heat | Check the water heater setting |
| Cycle ends but the dishes are still dirty | A heating fault, not a detergent problem | Keep baby bottles out of this machine for now |
| E01 returns straight after a reset | Element, relay or wiring needs repair | Stop retrying and book a diagnostic |
What Does a Bosch Dishwasher E01 Error Mean?
E01 means the dishwasher has found a failure in its heating circuit, so the water in the tub cannot reach the temperature the chosen program needs. The code page says dishes are then neither cleaned nor sanitized properly, which is the practical problem a homeowner sees long before any display message.
It helps to picture what the heater does in a cycle. Detergent works best in warm water, and the hot phases of a program also loosen baked-on grease and help the dishes dry. When the water stays cold, the cycle still runs to the end and looks normal from the outside, but the result is a plate that feels slick and a glass that is spotted. That is the sign people describe first, and it is the one worth believing.
E01 is a heating code, not a water-level or drain code. If your dishwasher fills and drains normally and the only complaint is cold water, you are in the right place. If it also leaves water behind, read our guide to a Bosch dishwasher that is not draining as well.
Is It Safe to Keep Using a Bosch Dishwasher With E01?
Maybe, for a short time. The code page says the dishwasher can still run, but the dishes will not be properly sanitized, so it should not be trusted for baby bottles or anything that needs high-temperature sterilization.
- Rinse and hand-wash the critical items. Bottles, cutting boards that touched raw meat and anything a child puts in the mouth deserve hot water you can trust.
- Watch for a burning smell. A smell from inside the tub is a reason to stop at once and switch the breaker off.
- Do not run repeated test cycles. If E01 comes back every time, extra cycles only waste water and detergent.
- Plan the visit within days. The machine is usable, but the fault does not fix itself and the cleaning result keeps getting worse.
Three Causes Behind a Dishwasher That Will Not Heat
The code page lists three causes, and all three are marked as jobs for a technician, because they sit under the tub or on the control board.
- Burned-out heating element. The element has failed from age or mineral buildup and no longer produces heat. It is the first cause the page lists, and the one that fits cold water through the whole cycle.
- Faulty control board relay. The relay on the main board that switches power to the element has failed, so the element is healthy but never gets power.
- Wiring harness damage. Corroded or disconnected wires between the board and the element break the circuit.
A technician separates the three with a meter: continuity on the element tells you whether the part is open, and voltage at the connector tells you whether the board is sending power. Without those two readings, replacing the element is a guess.
Can You Reset a Bosch Dishwasher E01 Error?
You can try, but the code page says a power reset rarely resolves E01. Turning the breaker off for 60 seconds and restoring power clears a temporary electronic glitch, and nothing more than that.
If E01 disappears and the next cycle heats the water, the cause was a glitch and you can carry on. If it comes back immediately, the element or its circuit needs professional repair, and each reset only delays the visit. Note what happened after the reset, because a technician finds it useful to know whether the code returned at the start of the heat phase or later.
Checks to Run Before You Book
The first three checks below come from the code page as safe for a homeowner, and none needs a panel removed. They rule out the cheap explanations and give the technician a clean starting point.
- Run the kitchen faucet until the water is hot, then start the dishwasher so it receives hot water from the first minute.
- Confirm your water heater is set to at least 120°F (49°C), using a kitchen thermometer at the faucet.
- Switch the dishwasher off at the breaker for 60 seconds, restore power and run a short test cycle.
- Open the door right after the cycle and feel the inside walls. Cool walls point to a heater that never switched on.
If the dishes are still cold after a cycle, the code page says the heating element is the likely issue. Do not remove panels to look at it yourself: the element sits beside live wiring and water.
E01, E09 and E12: Which Heating Code Is It?
Bosch shows three codes that touch the heat, and they are easy to mix up. Each one has its own page on this site, and they point to different parts of the machine.
- E01: the heating element itself has failed, so the water never warms up.
- E09: a heating circuit or heat pump fault, described on the E09 code page.
- E12: limescale on the heat pump, covered on the E12 code page, which insulates the heater and slows the warm-up.
If you are unsure which one you have, write down the exact code and when it appeared in the cycle.
What Happens at the Visit
The technician reads the code, checks the hot water supply to the machine and measures the element for continuity before taking anything apart. If the element is open, it is replaced. If it is sound, the board relay and the wiring are tested next, so a good part is not swapped for nothing.
Our Bosch dishwasher repair service covers the element, the relay and the harness. You can book a visit or tell us what the water felt like so the right part comes on the first trip. For the cost side of the decision, see what Bosch dishwasher repairs cost, and for upkeep that keeps the heater clean, the Bosch dishwasher maintenance guide.