Entering Service Mode and Starting a Test Cycle in a Bosch Silence Plus 50 dBA Dishwasher

 A Bosch Silence Plus 50 dBA dishwasher, known for its quiet 50 dBA operation. This model’s service mode enables diagnostic tests to pinpoint issues. The Bosch Silence Plus 50 dBA dishwasher is designed for ultra-quiet operation, but like any appliance, it can encounter problems. Fortunately, Bosch engineers built in a service diagnostic mode (test program) to help troubleshoot issues. Entering this mode allows you to run a special test cycle that checks the dishwasher’s functions and reports any error codes (fault codes) indicating specific problems In this article, we’ll explain how to enter service mode on a Bosch Silence Plus 50 dBA dishwasher and start the diagnostic test cycle, discuss what the test cycle is used for, and provide a detailed explanation of Bosch error codes. We’ll also cover important safety warnings (there are risks in DIY appliance repair) and gently remind you when it’s best to call a professional – such as Appliance Fix Lab in Winnipeg or Toronto – for Bosch dishwasher repair.

What is the Service Test Mode, and Why Use It?

Modern Bosch dishwashers (including the Silence Plus series) have a built-in service test program to assist in troubleshooting. Service mode (diagnostic mode) runs the dishwasher through a special cycle where it self-checks all major components (water inlet, wash pump, heater, drain pump, sensors, etc.). If something is wrong, the dishwasher will report an error code at the end of the test. This test cycle essentially simulates a regular wash but is designed to detect malfunctions and help pinpoint their cause.

Using the service test can save time and money by identifying the problem before you start replacing parts. Bosch recommends trying a diagnostic cycle (and a reset) before calling a technician. It gives you a better understanding of what’s wrong – for example, whether a no-drain issue is due to a clogged filter or a bad pump. The service mode is the same for Silence Plus 50 dBA models in Europe and North America, so the procedure to start the test does not vary by region. No matter where your Bosch was made, you can enter the diagnostic cycle using the steps below. (In older Bosch models without a digital display, the test mode will instead blink certain LED lights to signify error codes. In Silence Plus models with a display, you’ll see an “E:<number>” error code on the screen.)

Note: Running the diagnostic cycle is for testing and diagnostic purposes only. It won’t fix an issue by itself – but it will identify if a component is faulty or if an error condition (like a leak or overfill) is present. Always make sure the dishwasher is empty and has water supply turned on before running the test mode, so that the test can complete properly without spraying water on dishes or running dry.

How to Enter Service Mode on a Bosch Silence Plus 50 dBA

Entering the service mode on the Bosch Silence Plus 50 dBA involves using a specific sequence of front panel buttons. Bosch has kept this procedure fairly consistent across models – typically requiring you to hold down two buttons while turning the machine on. On the Silence Plus series (which usually has physical buttons for cycle selection), the process is as follows:

1. Prepare the Dishwasher: Ensure the dishwasher is turned off. It’s best to start with the door closed and latched (for fully-integrated top-control models, have the door unlatched so you can press buttons, but you will close it to run the test). Make sure the dishwasher is empty of dishes and that you won’t need to interrupt the cycle.

2. Press and Hold Buttons: On the control panel, press and hold any two wash cycle selector buttons (the specific buttons can vary by model, but Bosch’s service manuals often refer to the 2nd and 4th buttons from the left). For example, on some Bosch dishwashers, you might hold the “Normal Wash” and “Rinse & Hold” buttons together – the key is holding two cycle keys at the same time. (If your Silence Plus has different cycle names, don’t worry – any two cycle buttons pressed simultaneously should work for entering diagnostics.)

3. Power On the Dishwasher: While continuing to hold those two buttons, press the ON/OFF (Power) button to turn the dishwasher on. Keep holding the two cycle buttons for a few seconds until you see a reaction on the display or LEDs.

4. Release and Confirm Service Mode: Release the buttons. If done correctly, the dishwasher should now indicate it’s in service program mode. How do you know? On models with a digital display, you might see “0” or “P0” or some code flash briefly. On others, certain LEDs will start blinking. For instance, one Bosch tech tip says the light above the second button will be lit and the third button’s light will be flashing, confirming you’re in the special programs menu. (Each model may differ slightly in the light pattern, but if you entered service mode, something will change – e.g., lights flashing or a “diagnostic” indication on the display.)

5. Start the Test Program: Now, you need to start the diagnostic test cycle. In many cases, you press the same two buttons again (the ones you held before) to begin the test. On some models, you might have to select the test program first: for example, pressing one of the buttons cycles through test modes (showing “P1”, “P2”, etc.) – for most dishwashers, “P1” is the complete test cycle. If your Silence Plus displays “P1”, that’s the program you want. Then press the Start button (or the specific button indicated as “C” in manuals) to launch the test run. In simpler models, you may not see “P1”; just pressing the two buttons a second time or pressing the Start button will initiate the only test cycle available.

6. Close the Door (if applicable): If your model has the controls on top of the door (hidden when closed), you’ll need to shut the door once the test has started so that the cycle can run to completion. For front-control models, the test should run with the door closed as well. The dishwasher will now run through a sequence of operations automatically – typically filling with water, washing briefly, activating the heater, then draining. The entire test program usually lasts several minutes (often around 5-10 minutes).

7. Wait for the Cycle to Finish: Allow the diagnostic cycle to complete fully. Do not press any buttons or interrupt the dishwasher during this test. When the test program ends, the machine will display any error codes that were detected (or it might flash certain LEDs to indicate a fault code). For models with a display, you’ll see an “E:<number>” code if a problem was found, or “E:0” (or no error) if everything passed. On units without a display, a combination of indicator lights will be lit to signify the error (for example, Clean light flashing, or Clean and Sanitized lights together – these correspond to specific codes per the service manual).

8. Record or Note the Error Code: Make note of any error code shown. Often, the code will remain in the display until you turn off the dishwasher. If multiple faults are detected, the display may cycle through codes or show the highest priority one first. For blinking-light indications, consult your manual’s fault code chart (or see common codes below). To exit service mode, simply press the ON/OFF button to turn the dishwasher off.

9. Interpret the Results: Now it’s time to translate the error code (if any) into actionable information. Bosch error codes consist of “E” followed by two numbers (or one number for older models). In the next section, we’ll list the common Bosch dishwasher error codes and their meanings. For example, E24 is a very common code indicating a draining problem, whereas E15 means the machine detected a leak and activated the safety float switch. Understanding these codes will tell you what kind of issue to investigate or repair.

Important: If the test cycle doesn’t start, or nothing happens, turn off the dishwasher and try the button sequence again. Timing can be finicky – be sure to hold the two buttons firmly before powering on, and don’t release them until after the machine turns on. If you’re still unable to enter diagnostics, double-check which buttons apply to your model (the “2nd and 4th” rule usually holds, but there are exceptions). Also, ensure the dishwasher has power and is not already in some error state that prevents entering service mode.

Bosch Silence Plus Dishwasher Error Codes Explained

When the service test finishes, any fault it finds will be shown as an error code. Additionally, even outside of diagnostic mode, your Bosch Silence Plus 50 dBA might display an error code during normal use if it encounters a problem (for instance, some models will show an “E:__” code on the time display or blink a combination of lights). Below we’ve compiled a detailed list of common Bosch dishwasher error codes and what they mean. These explanations apply to the Silence Plus 50 dBA and many similar Bosch models:

• E01 – E06: Control or Sensor Faults. Codes E01 through E06 generally point to internal electronic issues or sensor failures. For example, E01 indicates a problem with the motor circuit on the main control board (the power module). E02 and E03 relate to faults in the control board’s relays (such as a sticking or failed relay that controls a component). E04 means the self-test detected a fault in the heating circuit electronics. E05 points to an issue with the wash arm diverter or its circuit, and E06 is a code for a door sensor fault (the door latch sensor isn’t reporting correctly). These codes are more complex and often not easily DIY-fixable – they may require replacing the control board, sensor, or other electrical components. If you see any E01–E06 error, it’s usually best to have a professional diagnose the control module and related parts.

• E07 – Heating Fan Fault (Drying System). An E07 error (not as common on Silence Plus 50 dBA unless the model has special drying features) indicates a problem with the drying system fan. Many Bosch dishwashers use a Zeolite drying system or additional heating for drying; E07 means the drying fan motor is defective or not working. If this occurs, the dishwasher might not dry dishes properly. Solution may involve checking the fan or Zeolite unit – likely a job for a service technician.

• E09 – Heating Circuit Failure. Error E09 is a common code on Bosch dishwashers indicating a fault in the heating circuit (heat pump). Bosch Silence Plus models use a combined circulation pump and heater assembly (often called a heat pump). E09 typically means the heating element is burned out or the heat pump has an internal fault. You might notice the dishwasher was not heating water, or the cycle took too long before this error. Resolving E09 usually requires replacing the heat pump unit or heating element. This is a more involved repair – if you’re not experienced, seek professional help.

• E12 – Limescale Buildup. E12 means there is limescale (mineral) buildup in the heat pump or heating element. Over time, hard water can cause mineral deposits, which insulate the heater and affect performance. The dishwasher is telling you it needs to be descaled. The solution is to run a descaling cycle or use a Bosch dishwasher descale product to remove mineral deposits. Regular use of dishwasher salt (if your model has a water softener) can help prevent E12. This code by itself isn’t a broken part – it’s a maintenance issue.

• E14 – Flow Meter Sensor Issue. E14 indicates a flow meter failure or a water filling. The flow meter is a sensor that measures how much water enters the dishwasher. An E14 code suggests the dishwasher isn’t detecting water flow correctly – water might not be entering at the expected rate. This could be due to a bad flow sensor, a problem with the inlet valve, or even a kink in the fill hose. Check that your water supply is on and the hose isn’t kinked first. If the water is indeed flowing but E14 persists, the flow meter component may need replacement. E15 – Water Leak Detected (AquaStop Activated). An E15 error is very common, and it means the dishwasher’s safety float has detected water in the base pan (internal leak). Bosch dishwashers have a safety system that catches leaks; if a leak or overflow is detected, it triggers the float switch and pumps out water to prevent flooding. When E15 appears, the dishwasher will usually stop and may drain continuously. Causes: a leaky hose or loose connection, too much foam from detergent, or water spilled into the base. The immediate step is to turn off water and power to the unit. You can tip the dishwasher forward to drain the base pan (have towels ready) and reset the error (E15 usually clears after the water is removed and the unit is restarted). However, be cautious – if you’re seeing E15, you should investigate the source of the leak. It could be a bad door gasket, a loose pump seal, or another internal leak. If not confident, call a technician, because running the machine with an active leak can cause electrical damage. (On models with AquaStop hose, E15 can also indicate that the leak-safe hose detected moisture.)

• E16 / E17 – Filling (Water Inlet) Fault. Errors E16 and E17 both relate to water filling problems. In Bosch documentation, they are often listed together. These codes mean the dishwasher isn’t getting water when it should, or it’s over-filling. Possible causes: the water supply valve is turned off or the inlet hose is kinked (resulting in not enough water – underfill), or the inlet valve could be stuck open (causing too much water – overfill). Essentially, E16/E17 indicate the dishwasher can’t properly control the incoming water flow. Make sure the tap is open and water pressure is normal. Check the inlet hose and inlet valve. Sometimes debris can clog the valve screen, restricting flow (leading to E16). If the machine is overfilling (water in the tub when off), the inlet valve might be faulty and not closing (which could trigger E17 or even E15 if it leaks into the indicator base). Addressing these errors might involve cleaning or replacing the water inlet valve.

• E18 – Water Level Low / Filling Timeout. E18 means the water level in the dishwasher is too low or the unit did not fill with enough water in the allotted time. This can overlap with the causes of E16/E17. Bosch specifically notes E18 as an issue where either not enough water is getting in or it’s being pumped out too soon. Check that the supply is on and the hose isn’t blocked. Also, low water pressure in the home can cause this. In some cases, a failing flow meter or inlet valve might throw E18. Ensuring a minimum flow rate of about 10 liters/minute is recommended. If you continue to see E18, the inlet valve or flow sensor may need service.

• E19 – Dispenser Circuit Fault. E19 indicates an electrical fault with the detergent dispenser solenoid or its circuit. This code suggests the control board can’t activate the dispenser door (which opens to release detergent). It could be a bad dispenser actuator, a wiring issue, or the control board’s dispenser relay. In practical terms, if your dishwasher isn’t releasing soap and you see E19, the dispenser unit likely needs replacement or electrical repair. A temporary workaround is to use dishwasher tablets that you can place at the bottom of the tub, but ultimately, you’d want to fix the dispenser. Since this is an electrical component fault, consider professional repair.

• E20 – Heat Pump Error (Heater Fault). E20 is a code for a heat pump internal heater fault. It means the dishwasher detected an issue with the heating element circuit (similar to E09). On some models, E20 can specifically indicate a problem detected with the wash motor’s ability to heat. If you see E20, the dishwasher likely didn’t heat the water properly. The troubleshooting is similar to E09: check the continuity of the heater, and inspect the control board for burn marks on the heater relay. Often, this code results in replacing the heat pump assembly or the control board.

• E21 – Wash Pump Blocked or Stuck. E21 means the circulation pump (main wash pump) is blocked or jammed. The control detected that the pump isn’t turning as expected. This can happen if something like a piece of broken glass or a food chunk got past the filter and is obstructing the pump impeller. It could also indicate a seized motor. If you feel handy, you can remove the filters and check the pump area for debris (always disconnect power before poking around). Sometimes, you may hear a hum and no water spraying when the pump is jammed. Cleaning out the pump or, if the pump motor failed, replacing the pump will resolve E21.

• E22 – Clogged Filter (Easy Fix!). E22 is one of the simpler errors – it indicates the dishwasher filter is dirty or blocked. Bosch dishwashers monitor how water flows and will throw E22 if the fine filter screen is clogged with food debris. The fix is straightforward: clean the filter. Remove the cylindrical filter unit at the bottom of the dishwasher, wash out all the gunk under running water (use a soft brush and mild soap). Also, check the area beneath where the filter sits for any food particles. Keeping the filter clean (Bosch recommends cleaning it every few months) prevents this error. After cleaning, reset the dishwasher, and E22 should clear. (Note: E22 by itself doesn’t stop the dishwasher mid-cycle; it often shows at the end of the cycle as a reminder that flow was restricted.)

• E23 – Drain Pump Failure. E23 signifies an issue with the drain pump or its circuit. This is an error that points to the drain pump not working electrically – possibly a shorted pump or a wiring fault. If the dishwasher attempted to drain and sensed that the pump didn’t run, it throws E23. In some cases, a clogged pump can also cause E23 (overlap with E24/E25), but officially, E23 is more about the pump motor or its drive circuit being faulty. You’ll likely need to inspect the drain pump: check if the impeller is jammed, and test the pump’s continuity with a meter. If the pump coil is open (no continuity) or the pump is getting voltage but not spinning, the pump unit should be replaced. Sometimes, a failure on the control board can also cause drain pump errors (if the relay or triac that powers the pump is bad). Given the complexity, consider a professional diagnosis for E23 if basic checks don’t find a simple clog.

• E24 – Drainage Problem. E24 is a very commonly seen error on Bosch dishwashers. It means the dishwasher is not draining properly. Typically, E24 is triggered by blockages in the drain path. Common causes include: a clogged filter (which we addressed with E22), a kinked or clogged drain hose, or an improperly installed garbage disposal plug (if the dishwasher’s drain is connected to a disposal, the knockout plug must be removed). Bosch’s tips for E24 are to check that the drain hose isn’t bent or blocked and that the kitchen sink drain is clear. Also, verify that the little cover on the drain pump (inside the dishwasher, under the filter) is snapped in place properly – if that cover is loose, water can’t flow out well (this relates to E25 too). How to fix E24: first, clean the filters and make sure the sump area is clear. Next, inspect the drain hose from the dishwasher to the sink – straighten any kinks and flush it if possible. If you recently installed a new garbage disposal, ensure the plug is knocked out. After addressing these, restart the dishwasher. If E24 persists, the issue might be a failing drain pump or a blockage in the pump itself. E24 can usually be fixed with some cleaning and isn’t a serious mechanical failure in most cases.

• E25 – Drain Pump Cover Off or Pump Blocked. E25 is closely related to E24, and often these two come up together. E25 means the drain pump is either obstructed or the pump cover is not properly in place. Inside the dishwasher, beneath the filter, there’s a small removable cover that provides access to the drain pump impeller. If someone removed it to clean the pump and didn’t lock it back correctly, E25 will be triggered because the pump can’t build pressure to drain. E25 can also occur if something like broken glass is jamming the impeller. To fix an E25 error, do the following: Remove the filters, then take off the pump cover (use a spoon handle to pry it up as Bosch suggests). Check for debris inside the pump well – broken glass, food bones, twist ties, etc. Clean out any debris and sponge out any standing water. Be careful, as debris can be sharp. Once clear, reinstall the pump cover securely – it should click and sit flush. A loose or missing pump cover will cause recurrent draining errors. After this, E25 should clear on the next run. If not, and the pump was clear, the drain pump motor might be failing and not spinning up to full speed, which would require replacement.

• E27 – Input Voltage Too Low. E27 is an error that indicates the supply voltage to the dishwasher is out of range (too low). This is more common in regions with a 120V supply. If the voltage in your home dropped significantly (brownout) or the unit isn’t on a dedicated circuit and experiences a voltage drop, it can show E27. It’s telling you, “Hey, I’m not getting enough power.” If you see this, you might want to check if other heavy appliances are on the same circuit or if there was a power surge/drop. The solution per Bosch is to ensure proper electrical supply – sometimes just resetting the breaker can clear transient errors. If the code persists, an electrician should check the house wiring. (Note: In some Bosch documentation, E29 is used similarly for voltage issues on 240V models – but on 120V North American models, E27 is the code.) Ensure your dishwasher is connected per electrical specs. If other appliances are running fine, E27 could also result from a control board issue misreading voltage, but that’s rare.

• Other Codes (E28, E30, etc.): Bosch has a wide range of fault codes (E01 up to E30 and beyond in newer models). Some are very model-specific. For instance, E26 and E28 can relate to the water switch (diverter valve) issues on models that have a separate spray zone control. E30+ codes may appear on Wi-Fi-enabled models or indicate communication errors. If you encounter an error code not listed above, refer to your model’s manual or look up Bosch’s official error code documentation. Bosch’s owner support website provides a comprehensive error code listwhich can help decipher less common codes. In general, any error code E01 through E30 that you don’t recognize is a technical fault – try a basic reset of the dishwasher (turn off power for 5 minutes, then on). If the code returns, it likely needs a part replaced or professional service.

As you can see, Bosch error codes give a fairly clear idea of what went wrong – from leaks (E15) to heating failures (E09/E11) to drain issues (E24/E25) and more. Knowing these codes can guide you in what to do next, whether it’s a simple DIY fix (cleaning a filter) or calling in an expert for a complex repair.

Safety Warnings for DIY Repairs

Working with appliances can be dangerous if proper precautions are not taken. Dishwashers are high-voltage devices with water involved, so safety is paramount. Before attempting any repairs or even opening access panels, ALWAYS disconnect the dishwasher from power (unplug it or flip the circuit breaker off). Also, turn off the water supply if you’ll be removing hoses. Electric shock is a serious risk – in some countries, only licensed technicians are allowed to service appliances for this reason. There are live electrical parts inside a dishwasher; touching the wrong component with power on can result in injury or worse. Additionally, be cautious of sharp edges inside the machine and hot water if you’ve run a cycle recently.

If you’re running the service test mode, it’s generally safe to do so with the machine closed (it’s an automated test). Just don’t try to open the door mid-cycle – hot water could spray out. Also, do not bypass any safety features. For example, some folks might be tempted to run the dishwasher with panels off to see leaks – this is not advised unless you really know what you’re doing, as exposed wiring could contact metal or water.

Remember that even after the dishwasher is unplugged, some components (like capacitors in the control board) might hold an electrical charge for a short while. And mechanically, there are moving parts (like the drain pump and fans) that could start unexpectedly if the machine were to turn on.

In summary: When in doubt, do not risk your safety. It’s one thing to clean filters or unclog a hose – those are fine for a homeowner to do with proper precautions. But for electrical faults, heater replacements, or anything requiring internal access, consider whether you have the right tools and knowledge.

When to Call a Professional

While we’ve armed you with knowledge on entering service mode and understanding error codes, some issues go beyond simple fixes. If the diagnostic test reveals a serious fault (for instance, a heater failure or a control board error), or if you’re not completely comfortable performing a repair, it’s wise to contact a professional appliance repair service. Bosch dishwashers are sophisticated machines, and improper repair attempts can lead to further damage. Bosch’s documentation suggests that only trained technicians should perform certain repairs due to complexity and safetyCalling a professional is especially recommended if:

• The error code points to an electrical or electronic problem (E01-E06, E11, E14, E19, etc.). These often require testing circuits or replacing control units.

• You have tried basic fixes (cleaning filters, checking hoses) for drain or fill errors, and the issue persists.

• There are signs of a water leak inside the appliance (which can be tricky to locate and properly fix without proper tools).

• The dishwasher is still not functioning correctly, even after running the test cycle and clearing minor clogs.

For those in Winnipeg or Toronto (and surrounding areas), Appliance Fix Lab is a specialized company that services Bosch appliances (among others). Our technicians are experienced in diagnosing Bosch dishwashers and can fix issues efficiently and safely. Sometimes having an expert take a look will save you time and prevent potential hazards. We can also ensure that genuine Bosch parts are used for any replacements, preserving the longevity of your Silence Plus dishwasher.

Unobtrusive Tip: Even if you’re a determined DIY-er, there’s no shame in getting professional help for complex appliance problems. A poorly executed repair can lead to bigger problems down the line – from electrical shorts to water damage in your kitchen. A skilled technician will not only fix the issue but also provide a guarantee on the work, giving you peace of mind. In the end, the goal is to have a smoothly running dishwasher and to avoid any risks or headaches.

By following the steps to enter service mode and understanding the resulting error codes, you can take the first step in diagnosing what’s wrong with your Bosch Silence Plus 50 dBA dishwasher. This empowers you with knowledge – whether you decide to fix the simple things yourself (like unclogging a filter) or call in Appliance Fix Lab for professional repair on the tougher problems. Remember to always put safety first during any appliance repair. With proper care and maintenance, plus timely professional help when needed, your Bosch dishwasher should stay running quietly and efficiently for years, keeping your kitchen chores hassle-free.

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