Bosch Dishwasher E09 Error Code: Step-by-Step Fix
Required Tools for this Fix
- Screwdriver
- Multimeter
- Replacement heat pump
Quick Summary Answer: The Bosch dishwasher E09 error code indicates a heating element circuit failure, meaning your dishwasher cannot heat the water during its cycles. The most common cause is a burned-out heating element integrated directly into the wash motor (heat pump assembly), which requires replacing the entire heat pump unit. To fix it, we recommend disconnecting the power, checking the heater terminals with a multimeter, and installing a new OEM heat pump assembly if the circuit reads as an open loop.
An E09 error on your Bosch dishwasher can bring your kitchen routine to a sudden halt. You will likely notice your dishes are coming out wet, cold, and dirty at the end of a cycle.
This guide will walk you through the entire process of diagnosing and fixing this problem yourself. We will help you determine if you need a simple reset, a new heat pump, or a control board repair.
Why Bosch Dishwashers Use a Heat Pump
Traditional dishwashers use a thick metal heating coil sitting at the bottom of the tub. Bosch engineered a different system to maximize space and energy efficiency. They integrated the heating element directly into the circulation pump, creating a single component called a heat pump.
+--------------------------------------------------------+
| Bosch Heat Pump Unit |
| |
| +--------------------+ +--------------------+ |
| | | | | |
| | Circulation Motor |=======>| Thin-Film Heater | |
| | (Pumps Water) | | (Heats Water) | |
| | | | | |
| +--------------------+ +--------------------+ |
+--------------------------------------------------------+
Inside this pump, water passes over a thin-film heating element before entering the spray arms. This design heats water rapidly and leaves more room inside the tub for large dishes.
The main drawback of this design is that if the heater fails, you cannot swap out just the heating element. You must replace the entire integrated heat pump assembly.
Quick Reference Diagnostic & Cost Table
Before we grab our tools, let us look at the general scope of this repair. Use this table to understand what to expect regarding time, tools, and budget.
| Diagnostic Step | Est. Time | Tools Needed | Cost |
|---|---|---|---|
| 1. Soft Reset System | 5 mins | None | $0 |
| 2. Accessing the Pump | 20 mins | Torx T20 Screwdriver, Towels | $0 |
| 3. Multimeter Testing | 10 mins | Digital Multimeter, Needle-Nose Pliers | $0 |
| 4. Replacing the Pump | 45 mins | Torx T20, Pliers, Hose Clamp Tool | $90 - $180 |
| 5. Testing Control Board | 15 mins | Flathead Screwdriver, Multimeter | $0 - $150 |
DANGER: ELECTRICAL SHOCK HAZARD. Always unplug the dishwasher from the wall outlet or switch off the dedicated circuit breaker in your home service panel before removing any panels. Make sure to shut off the water supply valve under the sink to prevent accidental flooding.
Step 1: Is It Actually Broken? (The Soft Reset)
Occasionally, a temporary power surge or control board glitch can trigger a false E09 code. We suggest performing a soft reset before tearing the machine apart.
First, press and hold the Start button for approximately four to five seconds. This action cancels the current cycle and starts the drain pump. Let the machine pump out any sitting water until the display reads 0:01 or 0:00.
Next, unplug the dishwasher’s power cord from the wall outlet. If your unit is hardwired, locate your home electrical panel and flip the breaker off.
Leave the power disconnected for a full ten minutes. This allows the internal capacitors on the control module to discharge completely.
Plug the unit back in or flip the breaker back on. Run a short rinse or quick wash cycle to see if the E09 code returns. If the code reappears within a few minutes, the heater circuit is truly failing, and we must proceed to physical testing.
Step 2: Accessing the Components
To test the heat pump, we need to access the lower section of the dishwasher. Depending on your kitchen layout, you may need to pull the dishwasher out completely from under the counter.
+-------------------------------+
| |
| Dishwasher Tub |
| |
+-------------------------------+
|=== Outer Lower Access Panel ==| <-- Remove Torx screws here
=================== Floor ===================
Start by removing the outer door panel if your model requires it, or simply remove the lower kickplate (toe kick) at the very bottom. You will find two or four Torx T20 screws holding this kickplate in place. Remove these screws and set them aside in a secure container.
Behind the toe kick, you will see a metal guard plate and some insulation. Carefully pull out the insulation and set it to the side.
For the absolute best access, we recommend pulling the unit completely out. To do this, unscrew the mounting brackets holding the dishwasher to the underside of your countertop.
Lower the leveling legs of the dishwasher using a flathead screwdriver or wrench. This gives you the clearance needed to slide the dishwasher out without scraping your cabinets or damaging your flooring.
Slowly slide the machine forward. Keep an eye on the drain hose, water line, and power cord to ensure they do not catch or stretch.
Step 3: Diagnostic Testing Checklist
Now that we have open access to the lower base of the dishwasher, we can test the heater. We will use a digital multimeter to check the resistance of the heating element.
- Identify the Heat Pump: Look under the right side of the dishwasher tub base. You will see a large, round plastic assembly with heavy wires running into it.
- Locate the Heater Plug: The heat pump has two separate wiring harnesses. One harness features thin control wires for the motor, while the other consists of three thick red wires (often with a green/yellow ground wire) going to the heater cover.
- Disconnect the Power Harness: Squeeze the locking tab on the thick red wire connector and gently pull it straight out of the heater housing.
- Set Up Your Multimeter: Turn your digital multimeter dial to the Ohms (Ω) setting. If your meter is not auto-ranging, set it to the lowest scale, such as 200 Ohms.
Heater Connector Terminals (on pump)
+-----------------------+
| [Pin 1] [Pin 2] [Pin 3] |
+-----------------------+
| | |
+-- 11Ω --+-- 11Ω --+
| |
+------- 22Ω -------+
With the harness disconnected, look closely at the male metal terminals inside the pump housing. You will see three flat pins side-by-side. Let us test them using your multimeter probes.
Place one probe on Pin 1 (left) and the other probe on Pin 2 (middle). You should see a reading between 10 and 13 Ohms.
Next, place one probe on Pin 2 (middle) and the other on Pin 3 (right). Again, you should see a reading between 10 and 13 Ohms.
Finally, place your probes on Pin 1 (left) and Pin 3 (right). This tests the entire heater coil circuit, and you should read between 19 and 24 Ohms.
If your multimeter displays OL (Open Loop), 1, or an extremely high resistance value during any of these tests, the heating element has burned through. The circuit is physically broken, and you must replace the heat pump assembly.
Step 4: Detailed Step-by-Step Replacement Guide
If your test confirmed a dead heating element, you need to swap the pump. We suggest ordering an official OEM Bosch replacement heat pump that matches your model number.
Old Pump New Pump (Updated Design)
+-----------+ +-----------+
| 85mm | | 75mm |
| Diameter | | Diameter |
+-----------+ +-----------+
|
v
(Requires adapter cable)
Note: Bosch redesigned their heat pumps over the years. If you are replacing an older 85mm pump with the newer 75mm pump, your replacement kit will include an adapter wiring harness. Follow the included instructions to plug this adapter in correctly.
Preparing the Base for Removal
Lay a few old towels down on the floor behind and underneath the dishwasher. We will be tipping the dishwasher onto its back, and some residual water will spill out of the sump.
Carefully tip the dishwasher completely onto its back panel. This position gives you a clear view of the entire plastic bottom pan (the base).
Locate the heavy tension springs on both sides of the dishwasher door. Unhook the door springs and tension cables from the base frame to keep them from snapping or stretching.
Separating the Base from the Tub
Look for the screws securing the plastic base to the metal tub. There are usually two screws on the bottom and sometimes two near the front legs.
Locate the metal tabs that snap the tub to the plastic base. Use a flathead screwdriver to gently pry these plastic tabs back, releasing the base.
+---------------------------------------+
| Metal Tub |
+---------------------------------------+
/ \ / \
/ \ <-- Pry plastic tabs -- / \
+-----+ +-----+
| Plastic Base |
+---------------------------------------+
Carefully pull the plastic base down about three to four inches away from the metal tub. Do not rip it off completely, as there are still several wires attached to sensors and pumps inside.
Locate the optical water level sensor and the flood switch assembly on the base. Unclip their wiring harnesses so you can swing the base further out of your way.
Removing the Defective Heat Pump
Look at the main wash pump sitting in the center-right of the base. It is suspended by a soft black rubber strap.
Slide the rubber suspension strap off the motor housing tab. The pump will now hang loose, supported only by its plumbing connections.
Locate the metal Oetiker clamp (pinch clamp) holding the pump’s outlet to the main water distribution assembly. This is a one-time-use metal band.
Pinch point
|
\ /
+--[###]--+
| Clamp | <-- Twist or cut here to release
+---------+
Insert a flathead screwdriver or a pair of side-cutters into the pinched ear of the metal clamp. Twist and pry hard until the clamp snaps open, then slide it off the rubber hose.
Gently wiggle the heat pump while pulling it away from the rubber sump connection. Work the pump back and forth until the main intake port slips out of the black rubber sump seal.
Installing the New Heat Pump
Clean any slime, scale, or debris out of the black rubber sump port. A clean surface ensures a watertight seal for the new pump.
Apply a small drop of liquid dish soap around the inner rim of the rubber sump seal. This acts as a safe lubricant to help the new pump slide in smoothly.
Take the new heat pump and push its main intake port firmly into the rubber sump seal. Make sure it seats all the way in without pinching or folding the rubber.
New Pump Port Rubber Sump Port
+---------+ +===\ /===+
| | ===========> | |===| | (Apply dish soap)
+---------+ +===/ \===+
Slide a new screw-type hose clamp (usually a 1-inch or 1.25-inch stainless steel worm-gear clamp) over the outlet hose. Push the pump outlet onto the plastic water distributor, slide the clamp over the joint, and tighten it securely with a flathead screwdriver or nut driver.
Hang the new pump back onto the plastic base chassis using the black rubber suspension strap. This strap is vital because it dampens motor vibrations during operation.
Reassembling the Dishwasher
Plug the wiring harnesses back into the new pump. The connectors are keyed, meaning they can only plug in one way.
Position the plastic base back over the metal tub. Guide the wires carefully to ensure nothing gets pinched between the plastic base and the steel tub.
Push the base and tub back together until you hear the plastic tabs click into place. Reinstall the securing screws you removed earlier.
Reattach the door tension cables and springs to their anchor points on the base frame. Lift the dishwasher back up to its upright position.
Slide the dishwasher back into its cabinet cavity. Reconnect the water supply line, drain hose, and power cord.
Step 5: Inspecting the Control Board and Wiring
What if you tested your heat pump and the multimeter showed a healthy 20 Ohms of resistance? If your heating element is fine, the E09 code is likely caused by a failed heater relay on the main control module.
Control Board (Power Module)
+-----------------------------+
| [Micro] -> [Relay]--x--\ | <-- Solder joint breaks or burns
| | | | |
+---------------+-----+---+---+
|
v
To Heat Pump
The main control board (often called the power module) is located in the bottom-right rear of the dishwasher, or inside the door panel on older units. We suggest inspecting this board for physical damage.
Unsnap the plastic housing containing the control module. Unplug the wire harnesses, noting where each one connects.
Carefully slide the circuit board out of its plastic protective housing. Look closely at both sides of the board under bright light.
Look for a black square component, which is the heater relay. Turn the board over and inspect the solder points directly beneath this relay.
You will often see a dark scorch mark, a melted plastic housing, or a cracked solder joint. When the dishwasher draws high amperage to run the heater, a weak solder joint will overheat, melt, and break the electrical circuit.
If you are skilled with a soldering iron, you can desolder the damaged relay and install a new one for a few dollars. Otherwise, you must replace the entire control module assembly to clear the E09 error.
Step 6: Reassembly and Calibration Run
With your new heat pump or control board installed, it is time to put everything back together and test your work.
Reattach the lower kickplate and metal guard plate. Hand-tighten the Torx T20 screws until they are snug.
Open the water supply valve completely and check for any immediate drips under the sink. Turn the household circuit breaker back on or plug the power cord in.
Open the dishwasher door and select a cycle that uses hot water, such as Auto or Heavy. Add a small amount of detergent to help break down any internal oils on the new parts.
Testing Phase Checklist
====================================================
[ ] Dry floor under dishwasher (helps spot new leaks)
[ ] Start "Auto" or "Heavy" wash cycle
[ ] Listen for wash motor starting (humming sound)
[ ] Wait 20 minutes and carefully open door
[ ] Check for hot steam rising from the tub
Let the dishwasher run for about 15 to 20 minutes. At this point in the cycle, the machine should be actively heating the water.
Carefully open the dishwasher door. You should feel a wave of warm or hot steam rising out of the tub, and the water inside should be hot to the touch.
Check the digital display. The E09 error code should be gone, and the timer should be counting down normally.
Finally, take a flashlight and peer under the dishwasher’s kickplate. Inspect the area around the new pump connections to ensure there are no slow water leaks.
FAQ Section
Can I run my Bosch dishwasher with an E09 error code?
Yes, the dishwasher will often still run its cycle, but it will do so using completely cold water. Your dishes will not be sanitized, grease will not break down, and the active drying cycle will fail. We suggest fixing the issue promptly to avoid hygiene problems and poor cleaning performance.
Is it possible to replace just the heating coil instead of the whole pump?
No, the thin-film heating element is permanently bonded to the metal sleeve of the wash motor housing during manufacturing. There is no way to separate or replace the heating element by itself. You must replace the complete heat pump assembly.
How do I know if my Bosch dishwasher uses the 75mm or 85mm pump?
Older Bosch dishwashers (typically built before 2013) use the larger 85mm pump. Newer models use the redesigned 75mm pump. We recommend searching for your dishwasher’s exact model number (found on the top or side edge of the inner door) on an appliance parts website to find the correct OEM replacement kit.
What causes the heating element to burn out in the first place?
The heating element usually burns out due to mineral scale buildup or running the unit with insufficient water. If calcium and lime build up on the thin-film heater, it cannot transfer heat to the water efficiently. The element then overheats and burns out, much like a light bulb filament.
Will replacing the heat pump void my manufacturer’s warranty?
If your dishwasher is still within its original one-year warranty window, you should contact Bosch factory service instead of attempting a DIY repair. Working on the unit yourself can void your warranty coverage. For older machines out of warranty, performing this repair yourself is a great way to save money.
Safety Precaution Notice
Before proceeding with any repair checklist: Always unplug the appliance from its electrical socket and turn off shutoff valves for incoming water (for washers and dishwashers). Discharge capacitors if working on motors.
