CDA F3 fault codewhat it means and how to fix it
Water is still coming in and the machine cannot stop it. Close the tap now — this is the one CDA code to act on before reading anything else.
Stop — this needs an engineer
Get a qualified appliance engineer to look at your CDA F3
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified appliance engineer, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What F3 means
CDA name F3 continuous water input, and it describes a situation rather than a component: water is entering the machine and the machine has lost the ability to stop it. Their instruction is two words long before the phone number — close the tap. Of everything on this site, this is among the small number of codes where the reading order genuinely matters. Go and close the tap feeding the dishwasher, then come back. A fill valve that has stuck open does not stop because a cycle has been cancelled or because the machine has been switched off at the wall.
An inlet solenoid is spring-closed and opened by power, so cutting the power should shut it — but a valve jammed open by grit or a torn diaphragm stays open regardless of what the electronics want, and that is the failure F3 usually describes. CDA’s machines also carry an electrically operated valve in the plastic housing on the inlet hose itself, which is why the hose must never be cut or the housing put in water. The only thing that reliably stops water arriving is the tap.
There will normally be an isolation valve under the sink, usually a small lever or a slotted screw head on the pipe running to the machine; if you cannot find it, the mains stopcock will do. This is also the reason we take a hard line on the tipping advice that circulates for dishwasher water faults. On a machine with a stuck inlet valve, draining the base and restoring power puts you back exactly where you were, except now with a machine you believe you have fixed and a tap you have turned back on.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Inlet valve stuck open | The most likely cause and the reason for the urgency. A failed valve stays open whether or not the machine has power. | Common |
| Pressure switch or level sensor faulty | The machine unable to tell how much water it has, so it keeps calling for more. CDA publish F5 separately for a pressure system failure. | Common |
| Siphoning from the drain connection | A drain hose fitted too low or without the required loop can siphon water through the machine continuously, which reads as water arriving that will not stop. | Occasional |
| Control board fault | The board holding the valve open when it should have closed it. CDA publish FE separately for a faulty electronic card. | Occasional |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£90–£200
A replacement inlet valve is typically £90 to £170 fitted. A pressure switch is similar. Both are modest jobs once the machine is out of the run.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related CDA fault codes
- FFGet it checkedWater inlet system failure. CDA want the tap checked and the hose filter cleaned, and both are free.Related: water intake
- F2Get it checkedCannot discharge water. CDA mention glass shards by name in their own remedy, which is a warning as much as a diagnosis.Related: same brand
- F1Stop — call an engineerOverflow. CDA tell you to unplug the machine and close the tap — power first, then water, and the order is worth understanding.Related: same brand
- F7Get it checkedOverheating. CDA publish it as a distinct fault from their two heater codes, which tells you something about what it means.Related: same brand
- F9Get it checkedDivisor position error. The machine has lost track of the valve that decides which spray arm gets the water.Related: same brand
Own a CDA dishwasher? Save it and its codes come first next time.
Related guides
Common questions about CDA F3
What do I do first?
Close the tap. Not cancel the cycle, not switch it off at the wall — close the tap. A stuck inlet valve keeps letting water through with the machine unplugged, so the water supply is the only thing that stops it.
Where is the tap for the dishwasher?
Usually under the sink: a small lever valve or a slotted screw head on the pipe feeding the machine, often colour-coded blue. If you cannot find it or it will not move, use the mains stopcock instead. It is worth locating it now rather than during the next one.
I switched it off at the wall and water is still coming in. Is that normal?
It is exactly what this fault looks like, and it is the reason CDA name the tap rather than the plug for this code. A healthy inlet valve is spring-closed and only opens when powered; one that has jammed open on grit or a torn diaphragm stays open with the power off, so removing power changes nothing.
Can it wait until the weekend?
Not with the water on. With the tap closed the machine is safe to leave as long as you like, so closing the tap buys you the time to book a convenient appointment.
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.