CDA F9 fault codewhat it means and how to fix it
Divisor position error. The machine has lost track of the valve that decides which spray arm gets the water.
Take care
Get a qualified appliance engineer to look at your CDA F9
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 F9 means
F9 is the most obscure entry in CDA’s table and the one nobody recognises, because the word divisor is not used anywhere in the kitchen. It refers to the diverter — a small valve inside the machine that switches the flow of water between the upper and lower spray arms. It is what allows a half load setting to wash only the top basket, and on a full cycle it alternates between the two so that both get their turn at full pressure rather than sharing a weaker flow. A position error means the machine cannot confirm where that valve currently is.
CDA say nothing beyond the name and an instruction to contact customer care, so what follows is what the fault means in practice rather than their words. The symptom is distinctive once you know to look for it: one basket washes properly and the other does not.
Plates in the bottom come out clean while mugs in the top come out with tea still in them, or the reverse. That is different from the everything-is-dirty picture you get from a failed wash pump or blocked filters, and it is the detail worth mentioning when you book, because it points straight at the diverter rather than at the pump. Before you do book, check the free explanation. A spray arm that cannot turn, or one with its jets blocked by scale and debris, produces the same one-basket-clean symptom for no cost at all.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Diverter valve or its motor failed | The literal reading of the code. The valve is inside the machine and CDA route it to their own service. | Common |
| Position sensor or microswitch faulty | The valve moving correctly but the machine unable to confirm it. Reported the same way, cheaper to put right. | Common |
| Spray arm blocked or jammed | Not this fault, but the same one-basket-clean symptom. Free to rule out and worth doing before booking anything. | Occasional |
| Debris obstructing the diverter | Something small and hard that got past the filters and stopped the valve reaching its position. | Occasional |
Can you fix it yourself?
Stop — this needs an engineer
What it costs to fix
Typical repair cost
£100–£220
Typically £100 to £200 fitted. Add time for getting an integrated machine out of the run, which most CDA dishwashers are.
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
- 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
- FFGet it checkedWater inlet system failure. CDA want the tap checked and the hose filter cleaned, and both are free.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
- F3Stop — call an engineerWater 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.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
Own a CDA dishwasher? Save it and its codes come first next time.
Related guides
Common questions about CDA F9
What on earth is a divisor?
CDA’s word for the diverter valve — the part that switches water between the upper and lower spray arms. It is what makes a half load setting possible, and on a normal cycle it alternates so each arm gets full pressure in turn.
The top basket is dirty and the bottom is fine. Is that this?
That is the classic picture, or the other way round. One basket clean and one not points at the diverter rather than the pump, because water is clearly being moved with force — it is just not being sent everywhere it should. Mention that symptom when you book.
Anything free to try first?
Yes. CDA’s own cleaning section has the spray arms off monthly: remove the lower basket and pull the lower spray arm upwards to remove it; for the upper arm, first remove its nut by turning it, and make sure that nut is securely tightened when you refit. Rinse them thoroughly, hold them up to the light and clear any blocked jets, and check both arms turn freely by hand once refitted. A blocked arm gives exactly the same one-basket complaint and costs nothing to fix.
My manual has no F9 row. Does the code still exist?
The CDI6242 manual is the one current CDA F-code manual without an F9 row; every other one — CDI4121, CDI4251, CDI4320, CDI4420, CDI6121, CDI6132, CDI6241, CDI6371 — prints it as divisor position error. The same table under other badges also carries F9, so a CDI6242 that shows it almost certainly means the same thing. CDA’s advice for every row of that kind is contact customer care.
Can I keep using it?
It will run, but half your load is not being washed properly. If you use it in the meantime, load everything you actually care about into whichever basket is still coming out clean.
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.