Written from manufacturer documentation — and clear about what they do not publish
Find out what your fault code means.
Type the code showing on your appliance. We will tell you what it means, whether it is safe, what you can try, and what a repair should cost.
1,021 codes across 91 brands · no sign-up · no manuals to wade through
What has gone wrong?
Start with the appliance, then pick the brand.
Boilers
Browse codesWashing machines
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Browse codesHobs
Browse codesRange cookers
Browse codesMicrowaves
Browse codesFridges and freezers
Browse codesHeat pumps
Browse codesAir conditioning
Browse codesEV chargers
Browse codesSolar and battery
Browse codesElectric showers
Browse codes
Most looked up
The codes people are searching for right now.
- F4ViessmannNo flame signal was detected during burner start on any two-character Vitodens, so the burner has locked out. Reset once; if it returns, call a Gas Safe engineer.Stop — call an engineer
- EA 227Worcester BoschThe boiler tried to light and never detected a flame, so it has shut the gas off and locked out. This is the most common Worcester fault code.Stop — call an engineer
- F.22VaillantThe boiler has shut down because there is not enough water in the system. Pressure has dropped below roughly 0.5 bar and it will not fire until you top it up.Get it checked
- 5ESamsungThe machine could not empty within the time it allows. On a Samsung this is the single most common code, and the filter behind the front flap is the usual answer.Get it checked
- E15BoschThe water protection system has activated — there is water in the base of the machine. Turn the tap off and call service. Do not tilt it, whatever else you read.Stop — call an engineer
- F05HotpointThe machine cannot pump out, so the door stays locked with water inside. Hotpoint treat it as an owner job, and two of their own documents agree on the causes.Get it checked
- Shower runs coldAll brandsWater flows but never heats. On an electric shower this is nearly always the supply, the flow through it, or an element that has stopped working.Get it checked
- F.75VaillantThe boiler cannot detect a rise in pressure when the pump starts, so it has locked out. Usually a failed pressure sensor or a pump that is not moving water.Get it checked
- Oven will not turn onAll brandsOn most range cookers the ovens will not heat until the clock has been set, and the timer has to be in manual mode. Three manufacturers publish this themselves.Usually simple to fix
- F1IdealSystem pressure has dropped below the minimum the boiler will run at. Topping it back up to 1.2 bar usually clears it straight away.Get it checked
- Safety noticeCandyA live UK fire recall covers built-in heat pump dryers under eight badges including Candy and Hoover. Machines modified before August 2025 are still at risk, and the manufacturers do not say so.Stop — call an engineer
- E01AlphaThe appliance tried to light and could not confirm a flame, so it has locked out. In winter a frozen condensate pipe is the most likely reason.Get it checked
The five things that actually go wrong
Codes differ between manufacturers. The faults behind them barely do — almost every code you will ever see is one of these five.
Pressure
The sealed system has lost water and the boiler will not fire without it.
Ignition and gas
The boiler tried to light and could not confirm a flame.
Overheat and circulation
Heat is being produced faster than the water can carry it away.
Fan and flue
The boiler cannot verify that combustion products are being cleared.
Sensors and electronics
A sensor or the control board is reporting a value that cannot be right.
How it works
Enter the code
Type it exactly as it appears, or as close as you can get. F.75, F75 and 75 all find the same page.
Read the answer first
One sentence at the top tells you what the code means. Below it, whether it is dangerous, what causes it, and what to try.
Fix it or get someone who can
Safe checks are written out step by step. If it needs an engineer, we say so plainly and help you find one.
Why you can trust this
Gas and electrical faults can kill people. We treat that seriously.
Clear about who checked it
Where a manufacturer says isolate the appliance and call someone, so do we. Every page is written from the manufacturer’s documentation and has not been reviewed by a registered engineer — it says so, and tells you exactly what it was written from.
Written from source, never copied
We read manufacturer technical documentation to establish the fact, then write the explanation ourselves. How we verify.
Kept current
Manufacturers revise their documentation and withdraw codes. We re-check pages against the current documentation at least every 18 months, and every page carries the date it was last updated.