What Does Error Code NO Mean on a Siemens Washing Machine?
Check that the cold water tap behind the machine is fully open and the inlet hose is not kinked or blocked, then restart the cycle — this resolves the majority of NO error cases (takes about 5 minutes).
Fault description
Error code NO appears on certain basic Siemens washing machine models when the appliance cannot detect water entering the drum at the start of a cycle, or when filling takes longer than the control board expects. It is functionally equivalent to error E17, which appears on more advanced Siemens models, and both point to the same underlying water inlet system.
When this error triggers, the machine will typically pause mid-fill or refuse to progress past the initial fill stage. You may hear the drum motor attempt to start, or you may notice complete silence after the door locks. The display will hold the NO code until the fault is cleared.
In most cases the cause is straightforward — a closed tap, a kinked hose, or a clogged inlet filter — and can be resolved without tools in a few minutes. Working through the steps below in order will help you identify and fix the problem efficiently.
Causes
- Water supply tap closed or partially closed — The cold water tap behind the machine must be fully open for adequate flow. Even a partially closed tap can restrict pressure enough to trigger the NO error.
- Kinked or crushed inlet hose — If the machine has been pushed back against the wall, the inlet hose can become kinked, blocking water flow entirely. This is one of the most common causes after moving or reinstalling the appliance.
- Blocked inlet hose filter mesh — A small mesh filter sits inside the inlet hose connection at the back of the machine. Over time it collects sediment and limescale, reducing flow to the point where the machine cannot fill correctly.
- Faulty or stuck water inlet valve — The inlet valve is an electrically operated solenoid that opens to allow water in. If it has failed mechanically or electrically, it will not open even when the control board sends the correct signal.
- Low mains water pressure — Siemens washing machines require a minimum water pressure — typically around 0.5 bar — to fill properly. Temporary low pressure from supply works or a shared building supply can cause the NO error to appear intermittently.
- Faulty pressure sensor or wiring — The pressure sensor (also called the water level sensor) tells the control board how much water is in the drum. If it is faulty or its wiring is damaged, the board may incorrectly believe the drum is not filling even when water is present.
Step-by-Step Fix
- 1
Check the water supply tap
Locate the cold water tap on the wall behind the machine and confirm it is turned fully anticlockwise (open). It is surprisingly common for this tap to be accidentally knocked partially closed. Turn it fully open, then restart the cycle to see if the error clears.
- 2
Inspect the inlet hose for kinks
Pull the machine gently away from the wall and run your hand along the full length of the inlet hose. Straighten any kinks or bends you find. Make sure there is enough slack in the hose so it does not kink again when the machine is pushed back into position.
- 3
Clean the inlet hose filter mesh
Turn off the water tap, then unscrew the inlet hose from the back of the machine — have a towel ready as some water will spill. Use a pair of pliers or your fingers to pull out the small mesh filter from the hose connection port. Rinse it under the tap and use an old toothbrush to remove any limescale or debris. Refit the filter, reconnect the hose firmly, and turn the tap back on.
- 4
Check household water pressure
Run a cold tap elsewhere in your home and observe the flow. If pressure seems unusually low throughout the house, contact your water supplier to check for a local supply issue. Wait until normal pressure is restored before running the machine again.
- 5
Power cycle the machine
Switch the machine off at the mains socket and leave it unpowered for two minutes. This allows the control board to fully reset. Switch it back on, select a short cycle, and observe whether the drum fills normally. This step can clear a temporary sensor or control board glitch.
- 6
Test the water inlet valve
If the steps above have not resolved the fault, the inlet valve itself may be defective. With the machine unplugged, disconnect the inlet hose and inspect the valve body at the back of the machine for visible cracks or corrosion. A multimeter can be used to test the solenoid coil for continuity — a reading of open circuit (OL) confirms the valve has failed and needs replacing.
- 7
Inspect the pressure sensor and its hose
The pressure sensor is usually located inside the top panel of the machine, connected to the drum by a thin rubber hose. Check that this hose is not split, blocked, or disconnected. If the hose is clear but the error persists, the sensor itself may need testing or replacing — at this stage it is reasonable to involve a service technician.
Affected models
Select your model to see its full troubleshooting page.
When to call a service technician
If you have worked through all the steps above — confirmed the water supply is open, cleaned the inlet filter, power cycled the machine, and visually inspected the inlet valve — and the NO error still appears, the fault is likely internal. A failed inlet valve solenoid, a defective pressure sensor, or a wiring fault between these components and the control board all require proper diagnosis with test equipment.
You should also call a service technician if you notice water leaking from the inlet hose connection after reassembly, if the machine makes an unusual buzzing sound during the fill phase (which can indicate a valve trying and failing to open), or if the error appears on every cycle without any obvious external cause.
Spare parts and service
Visit our partners for spare parts and service
Spare parts
Book a repair
Frequently Asked Questions
Is error code NO the same as error E17 on Siemens washing machines?
Yes, they describe the same fault — water not entering the drum within the expected time. The NO code tends to appear on simpler display models that cannot show alphanumeric codes, while E17 appears on models with a more detailed display. The causes and fixes are identical for both.
Can I still use my washing machine if the NO error keeps coming back?
It is not advisable to keep running the machine while the error is active. If the drum is not filling correctly, the machine may run a cycle with insufficient water, which can damage laundry and put unnecessary strain on the motor and heating element. Resolve the fault before using the machine again.
How do I reset the NO error code on a Siemens washing machine?
Once the underlying cause has been fixed, the error should clear automatically when you start a new cycle. If it does not, switch the machine off at the mains socket, wait two minutes, and switch it back on. Selecting a fresh programme after the reset is usually enough to clear the stored fault.
Could a frozen inlet hose cause the NO error in winter?
Yes. If your washing machine is installed in an unheated garage, utility room, or outbuilding, the inlet hose or the valve itself can freeze during cold weather, completely blocking water flow. Allow the hose to thaw naturally at room temperature — do not use a heat gun or open flame — before attempting to run the machine.
How long does it take to replace a water inlet valve on a Siemens washing machine?
For a confident DIYer with basic tools, replacing the inlet valve typically takes between 30 and 60 minutes. The valve is usually accessible from the back panel of the machine. Always unplug the machine and turn off the water supply before starting, and have towels ready to catch residual water in the hose.