Bosch Dishwasher E09 Error Code: Meaning, Causes & Fix

Heating circuit error — the dishwasher's heater is not working (heat pump/heater fault).

E09 is Bosch's heating fault: the control drove the heater (on modern Bosch machines the heater is integrated in the circulation 'heat pump') and the temperature didn't rise as expected. Dishes come out cold and wet, and cycles may run long or stop. The integrated heat-pump design means the heater and circulation pump are one assembly on many models — which is why E09 is usually a technician-grade repair despite the simple code. Bosch publishes E09 in its own error-code list as 'There is a heat pump internal heater fault/error', and its US support page for code 09 adds the instruction owners find surprising: do not try to resolve this one at home — close the water tap, switch the appliance off, and book an engineer. That firmness follows from where the fault lives. On these machines the heater is not a separate element under the tub that an owner can unplug and swap; it is built into the circulation pump assembly Bosch calls the heat pump, in the base of a built-in appliance, on a mains-voltage circuit. Bosch's published first step is the same as for its other electronic codes — reset power at the breaker for 30 seconds — because a transient control error should get its chance to clear. But Bosch draws the line exactly there: if E09 survives the reset, Bosch's documentation routes the machine to its engineers rather than to owner troubleshooting, and this page follows Bosch's line. What owners can usefully do is confirm the symptom (the checks below) so the visit starts from a verified no-heat report rather than a code alone.

What causes the E09 code on a Bosch dishwasher?

Heater element failure in the heat pump

The integrated element opens with age/scale.

Temperature sensor (NTC) fault

The control can't see heating that may be happening — sensor branch.

Wiring/control output

The heater is never powered.

The heater relay on the control board

The heat pump's element can only heat when the board's heater relay feeds it. A relay that has failed open leaves a healthy element unpowered — the control sees no temperature rise and reports the same E09 as for a dead element. This is why E09 diagnosis is a circuit diagnosis (element, then relay output, then sensor) rather than a part order: two of its three branches are not the heat pump at all.

Limescale as the slow accomplice — but note Bosch gives scale its own code

Hard water stresses integrated heaters, and scale history is worth reporting to the technician. Be precise, though: Bosch's list assigns limescale build-up in the heat pump its own code, E12, with descaling as the published remedy. An E09 machine is not a descaling job that got worse on paper — Bosch separates the maintenance state (E12) from the electrical fault (E09), and treating E09 with descaler wastes the weeks the heater circuit spends failing.

Checks to run before you replace anything

1. Confirm the symptom: open mid-cycle — is the water actually cold? Is there steam at cycle end? Cold + E09 = heater circuit.
2. Check for companion limescale history (hard water areas kill integrated heaters faster).
3. Run Bosch's published reset first: power off at the breaker for 30 seconds, restore, and start a hot cycle. Bosch prints this step against E09 in its own list; a code that clears and stays away through a full heated cycle was a transient. A code that returns in the first heating phase is the fault introducing itself properly.
4. Confirm the no-heat symptom physically so the service visit starts from evidence: mid-cycle, the tub water should be plainly hot and the door inner face warm; at cycle end, opening the door should release steam. Cold water, a cold door and wet, greasy-feeling dishes are E09's symptom set — and if the water is in fact hot, say so, because that combination redirects the diagnosis toward the temperature-sensing branch.

How to fix bosch dishwasher error code e09?

1. Technician testing separates element vs NTC vs board (the heat pump assembly is metered at its terminals).
2. Replace the heat pump assembly if the element is open (the standard cure — the heater isn't sold separately on integrated models).
3. Replace the NTC if the element is good and readings are implausible.
4. Technician sequence, so you know what you are paying for: the heat pump's heater is metered for continuity/resistance against the model's tech-sheet values; a proven element with no heat sends the test to the board's heater-relay output; a proven element and proven power send it to the NTC's readings. The repair that follows is the branch that failed — heat pump assembly, board, or sensor — and a quote that names one of those branches with its test result is a quote you can trust. Owner-side, after the repair: run the first heated cycle watched and confirm steam at the end — the first full cycle is where a marginal connector in the heater circuit announces itself if it is going to.

The part that usually fails: Heat pump (circulation pump + heater) assembly

Integrated design: heater failure = assembly replacement. That's why E09 quotes surprise owners — the part is the pump and heater together.

How to reset / clear the E09 code

Reset the cycle after repair; E09 clears when a heating phase shows a normal temperature rise.

On Bosch dishwashers, most error codes clear when the cycle is cancelled: hold the Start button for about 3 seconds until the display shows 0:01, let the machine pump out for a minute, then switch off. For many codes a control reset is the next step — switch the machine off, and on models with a physical power switch also cut power at the breaker for a few minutes. A code that returns straight after a reset is an active fault; Bosch controls re-detect it at the next self-check, typically within the first minutes of a new cycle.

Why does the E09 code keep coming back?

E09 returning after an assembly change points to the board's heater output or the NTC branch — full circuit diagnosis. E09 that returns after a heat pump change is the circuit finishing its sentence: the surviving branches — the board's heater relay and the NTC branch — were the fault all along, or a connector in the heater circuit is opening under heat. The tell is timing: a code that returns only deep into hot cycles is a connection expanding open; a code present from a cold start is a hard electrical failure. Either way the second visit should start from the first visit's test results, so keep the paperwork.

How to stop E09 coming back

• Heater element failure in the heat pump: The integrated element opens with age/scale.
• Temperature sensor (NTC) fault: The control can't see heating that may be happening — sensor branch.
• Wiring/control output: The heater is never powered.

Retrieving stored fault codes on Bosch dishwashers

Bosch dishwashers store the last errors in a fault memory that can be read in the customer-service/test program (entered with a two-button hold that varies by series — e.g. holding two program buttons while switching on). The test program also steps through fill, heat, wash and drain so a technician can see which stage re-triggers the code. The exact button pair for your series is in the service documentation; the fault memory survives a normal reset, which is why a Bosch technician can still see a code you cleared from the display.

Other Bosch dishwasher error codes

See the full list on the Bosch Dishwasher error codes hub.

Codes E09 gets confused with

E01 — Heat pump motor circuit fault at the main control board — Bosch's own published definition of E01 on its dishwasher error-code lists, with exactly one published owner remedy: reset power at the breaker for 30 seconds, and if the code is not resolved, contact Bosch Customer Support. Bosch defines this code more precisely than most.

E15 — Water in the base / leak protection active — the AquaStop safety system has detected water in the base tray and shut the water supply off. E15 is Bosch's leak-protection code: a float/ sensor in the base detected water, so the machine stopped and (on AquaStop models) the inlet safety valve closed.

E22 — Filter clogged — the filter system is blocked and needs cleaning (a maintenance code, not a breakdown). E22 is Bosch telling you the filters are too clogged to run properly: the control detects the circulation/drain behaving as if the filter is matted (because it is).

E07 — Drying fan / Zeolith drying fault on equipped Bosch models (the fan in the drying system is faulty) — model-specific member of the E0x block. E07 on Bosch dishwashers with the Zeolith/fan drying system reports a fault in the drying fan circuit: the fan that moves air through the Zeolith chamber (or over the tub in fan-drying models) isn't running or reporting.

Frequently asked questions

Related guides

Facts on this page were checked against manufacturer documentation: www.bosch-home.ca · www.bosch-home.com · www.bosch-home.com · washingcodes.com · manuals.plus · mans.io