The heat pump assembly is the most common cause — fast shipping across Canada and the USA
A Bosch dishwasher that won't heat water, displays E09 or E25 error codes, leaves dishes dirty or wet, or stops mid-cycle is almost always pointing to the heat pump assembly. On Bosch condensation-dry dishwashers, the heat pump is a combined circulation pump and in-line heater — it handles both water recirculation and heating in a single integrated unit. When it fails, the entire wash and dry system is affected.
Unlike traditional dishwashers with a separate heating element at the bottom of the tub, Bosch condensation-dry models use an integrated heat pump assembly that combines the main circulation pump motor with an in-line water heater, thermistor, and sealed housing. The pump recirculates water through the spray arms while the heater brings it to the required wash temperature. The same assembly also drives the condensation drying process. A failure in any component of this assembly — motor, heater element, or thermistor — typically requires replacing the entire unit.
The control board detected that the water temperature did not rise as expected during the wash cycle. The heating element inside the heat pump assembly has failed. This is the most common heat pump error code on Bosch dishwashers.
E25 can indicate a blocked filter or drain pump, but on some Bosch models it also appears when the heat pump is failing and causing circulation issues. Always check and clean the filter first before replacing the heat pump.
The most direct symptom. Water enters the tub but never gets hot. Dishes come out with food residue because the wash temperature isn't high enough to activate detergent enzymes. The heating element inside the heat pump has failed.
How to confirm: Run a cycle and carefully open the door mid-cycle (after the initial fill). If the water is cold or barely warm, the heater has failed.
✓ Shop 12008381 Bosch Dishwasher Heat Pump AssemblyPoor wash performance is often the first sign of a failing heat pump — the heater is degrading and water temperature is inconsistent. Grease and food residue that would normally be dissolved by hot water remains on dishes.
How to confirm: Check that the spray arms are not clogged first. If spray arms are clear and detergent is correct but dishes are still dirty, the heat pump is the likely cause.
✓ Shop 12008381 Bosch Dishwasher Heat Pump AssemblyThe control board monitors water temperature via the thermistor in the heat pump. If the thermistor fails or reports an out-of-range temperature, the board may abort the cycle and display an error code.
How to confirm: Note the error code displayed when the cycle stops. E09 directly indicates a heating fault. Contact us with your model number and error code for specific guidance.
✓ Shop 12008381 Bosch Dishwasher Heat Pump AssemblyThe heat pump housing can develop cracks or seal failures over time, causing water to leak into the base tray. This triggers the AquaStop float switch, which shuts down the dishwasher and may display an E15 error. If the leak originates at the pump housing, the heat pump assembly must be replaced.
How to confirm: Pull the dishwasher out and inspect the base tray for water. Trace the source of the leak — if it's at the pump housing or its connections, the assembly needs replacement.
✓ Shop 12008381 Bosch Dishwasher Heat Pump AssemblyBefore replacing the heat pump, always clean the dishwasher filter. A severely clogged filter can cause poor wash performance and in some cases trigger circulation-related error codes. Remove the filter assembly from the bottom of the tub, rinse under running water, and reinstall. If symptoms persist after cleaning, the heat pump is the next step.
This is an advanced repair — the heat pump is located at the bottom of the dishwasher and requires pulling the unit out and laying it on its back for access. 1. Disconnect power and water. 2. Pull the dishwasher out from under the counter. 3. Lay the dishwasher on its back. 4. Remove the base cover. 5. Disconnect the wiring harness and water connections from the heat pump. 6. Remove the mounting hardware and rotate the pump to release it from the tub. 7. Install the new assembly in reverse order. 8. Restore power and water and run a test cycle.
Can I replace just the heating element inside the heat pump? No — the heating element is integrated into the sealed pump housing and is not sold separately. The entire heat pump assembly is replaced as a unit.
Is this a DIY repair? Advanced — requires pulling the dishwasher out and laying it on its back. Mechanically experienced homeowners can complete it, but most people prefer a technician for this repair. Contact us if you need guidance.
What Bosch models use the 12008381 heat pump? It fits a wide range of Bosch SHE, SHP, SHX, SHV, and SHEM series dishwashers. Contact us with your model number to confirm fit before ordering.
How long does a Bosch heat pump last? Typical lifespan is 7–12 years. Failures are most often caused by motor burnout, heater element failure, or seal degradation leading to leaks.
