By Emily Rivers
Last updated 5th June 2025

Our boilers are an appliance in the home we do not give a second thought to, until the it is not working and we are left with the boiler not heating radiators or not giving hot water! When a boiler is not firing up or turns on but with a fault, the boiler will display a fault code to signal what is wrong so that you can get the boiler fixed or serviced. 

According to warranties, reputation, trustpilot reviews, customer service… these are some of the best boilers available in the UK;

  • Alpha boiler
  • Baxi boiler
  • Glow-Worm boiler
  • Ideal boiler
  • Potterton boiler
  • Vaillant boiler
  • Viessmann boiler
  • Vokera boiler
  • Worcester Bosch boiler

These are the boiler brands we will focus on when discussing and helping identify boiler fault codes most often experienced by homeowners.

Do all boilers have the same boiler fault codes?

Most boiler manufacturers follow a simple logic like E for Error or a F for Fault. The only challenging part is that different brands of boilers have their own codes. When you get your boiler installed, be sure to hang on to the manual and keep it in a safe place. If for any reason you have lost the manual, you can always download them off the boiler manufacturers website. Worcester Bosch has a list of all of their boiler user manuals here.

Cost to fix a boiler fault code

How much will it cost to fix my boiler fault code?

Fixing a fault code can often lead to a challenging few weeks of investigation work. When you first make contact with your heating engineer, and explain to them the fault code displayed with the make and model of your boiler, they should be familiar with the boiler to know the fault that the code represents. If not, they can look it up online or in your manual and begin the diagnostics.

Some faults are easy and quick to get the boiler back up and running but may need further investigation to identify the course of the problem, e.g.; a low pressure warning (F1 on an Ideal boiler or an A04 on a Vokera boiler), once you top up the system, the boiler will reignite and the fault code should disappear but why did the system lose pressure to begin with? This could result in the discovery of a slow leak through a pinhole on a radiator or a leaking valve or a rusty heat exchanger where water is slowly dripping through.

This means the cost to fix the initial boiler fault code, may just be an hour’s call-out fee but the cost to stop the fault from reoccurring could go into the hundreds, needing more than one call-out and parts ordered, replacing faulty or leaking components.

How much labour costs to fix a boiler fault

Per

Average cost

Replacing a faulty fan

Per hour 

£80 + £230 for the fan

Replacing a burnt-out pump

Per hour 

£80 + £210 for the pump

Diagnose a blockage in circulation (F25), bleed the radiators to remove air and check water quality for signs of debris

Per hour 

£100

Repressurising the system and spending time checking for signs of leaks

Per hour 

£120

Can I reset my boiler fault code?

The boiler fault code that has been displayed will only clear after the issue has been resolved and is no longer causing stress to the boiler. After repairing or replacing the cause, your gas engineer will reset the boiler which should then clear the fault code.

What does my boiler fault code mean?

As mentioned, different brands of boilers use their own unique codes for various faults, but two of the most common error codes displayed are either an F22 or an F25 fault code.

F22 error = the boiler’s water pressure has dropped too low, and the boiler will not fire up until the pressure has been restored. This fault code is used by Glow-Worm and Vaillant boilers.

F25 error = a safety shut-off code signalling to the boiler to switch off before the system overheats as the flow temperature is increasing at 5 degrees per second while the system is not circulating quick enough due to debris or air blockage. This fault code is used by Glow-Worm and Vaillant boilers.

To make it easy for you, HaMuch as a list of some brands of boilers with a click through to find the manual you need, just click on the make of your boiler;

Here are some useful common boiler error fault codes:

E-Error Codes

The “E-error codes” are usually broken down into;

E+2 codes, e.g.; E20, often requires a gas engineer, and might involve internal sensor errors

E+3 codes, e.g.; E110, E125, E131, often a fault that you can fix as they might just need radiators bled to remove air from the system

E119 boiler error code means low water pressure, so you can top up the pressure.

E+3 codes of higher numbers, e.g.; E151 – E167, might mean a programming error and will need a heating engineer to look at the system.

EA (Worcester) or F27 (Vaillant) 

Double check your manual, but this may refer to a blocked condensate pipe that may have frozen and will need carefully defrosting.

A1 or No code (Worcester) or F75 (Vaillant) F1 (Ideal) 

Water pressure has dropped significantly low code and will require a top-up of water to boost up the pressure.

EA (Worcester) or F75 (Vaillant)

This fault usually means that the boiler’s sensor is failing to connect with the pump 

Worcester Bosch Errors

A1 Low pressure need to top up the water in the system

C1 The fan has stopped running

EA No flame is detected

260 Sensor disconnected or no water in the boiler

C6 The boiler is running too fast or running too slow

C7 Fan not running or the airflow blocked

D1 The sensor is wet or damaged

E2 Flow sensor is shorted or damaged

E5 Primary flow sensor overheated

E9 The main heat exchanger has overheated


Estimates for common heating engineer jobs;

Rates for other trades

Fix a boiler fault code cost in the UK
Fix a boiler fault code cost in the UK (excluding VAT or callout charges)
Location in UKFix a boiler fault code cost
Fix a boiler fault code near London£120
Fix a boiler fault code near Birmingham£84
Fix a boiler fault code near Glasgow£88
Fix a boiler fault code near Leeds£78
Fix a boiler fault code near Liverpool£86
Fix a boiler fault code near Sheffield£80
Fix a boiler fault code near Edinburgh£88
Fix a boiler fault code near Manchester£84
Fix a boiler fault code near Belfast£68
Fix a boiler fault code near Bristol£82
Fix a boiler fault code near Leicester£82
Fix a boiler fault code near Cardiff£76
Fix a boiler fault code near Coventry£84
Fix a boiler fault code near Bradford£80
Fix a boiler fault code near Nottingham£80
Fix a boiler fault code near Newcastle Upon Tyne£88
Fix a boiler fault code near Brighton and Hove£100
Fix a boiler fault code near Derby£82
Fix a boiler fault code near Hull£76
Fix a boiler fault code near Plymouth£70
Fix a boiler fault code near Stoke-on-Trent£82
Fix a boiler fault code near Southampton£90
Fix a boiler fault code near Northampton£98
Fix a boiler fault code near Wolverhampton£86
Fix a boiler fault code near Luton£108
Fix a boiler fault code near Portsmouth£90
Fix a boiler fault code near Reading£118
Fix a boiler fault code near Norwich£88
Fix a boiler fault code near Milton Keynes£102
Fix a boiler fault code near Bournemouth£88
Fix a boiler fault code near Aberdeen£78
Fix a boiler fault code near Peterborough£86
Fix a boiler fault code near Bolton£84
Fix a boiler fault code near Swindon£100
Fix a boiler fault code near Southend-on-Sea£94
Fix a boiler fault code near Warrington£86
Fix a boiler fault code near Oxford£98
Fix a boiler fault code near Swansea£78
Fix a boiler fault code near Sunderland£88
Fix a boiler fault code near Slough£116
Fix a boiler fault code near Kingswood£82
Fix a boiler fault code near Telford£86
Fix a boiler fault code near Cambridge£90
Fix a boiler fault code near Ipswich£118
Fix a boiler fault code near Blackpool£78
Fix a boiler fault code near Middlesbrough£84
Fix a boiler fault code near Dundee£88
Fix a boiler fault code near Huddersfield£78
Fix a boiler fault code near York£74
Fix a boiler fault code near Poole£88
Fix a boiler fault code near Watford£118
Fix a boiler fault code near Newport£74
Fix a boiler fault code near Colchester£94
Fix a boiler fault code near Exeter£76
Fix a boiler fault code near Blackburn£78
Fix a boiler fault code near Crawley£112
Fix a boiler fault code near Gloucester£114
Fix a boiler fault code near Stockport£84
Fix a boiler fault code near Basingstoke£120
Fix a boiler fault code near Basildon£98
Fix a boiler fault code near Cheltenham£88
Fix a boiler fault code near Gateshead£88
Fix a boiler fault code near Worthing£98
Fix a boiler fault code near Rochdale£82
Fix a boiler fault code near Oldham£82
Fix a boiler fault code near Chelmsford£98
Fix a boiler fault code near Birkenhead£86
Fix a boiler fault code near Maidstone£96
Fix a boiler fault code near Gillingham£96
Fix a boiler fault code near Salford£84
Fix a boiler fault code near Solihull£84
Fix a boiler fault code near St Helens£86
Fix a boiler fault code near Worcester£88
Fix a boiler fault code near Lincoln£82
Fix a boiler fault code near West Bromwich£84
Fix a boiler fault code near Eastbourne£92
Fix a boiler fault code near Wakefield£80
Fix a boiler fault code near Wythenshawe£84
Fix a boiler fault code near Bedford£100
Fix a boiler fault code near Hemel Hempstead£112
Fix a boiler fault code near Preston£80
Fix a boiler fault code near Stevenage£108
Fix a boiler fault code near Southport£82
Fix a boiler fault code near Bath£84
Fix a boiler fault code near Harlow£110
Fix a boiler fault code near Sutton Coldfield£84
Fix a boiler fault code near Darlington£82
Fix a boiler fault code near Chester£86
Fix a boiler fault code near Hastings£88
Fix a boiler fault code near Nuneaton£84
Fix a boiler fault code near Halifax£78
Fix a boiler fault code near Hartlepool£84
Fix a boiler fault code near Aylesbury£108
Fix a boiler fault code near Doncaster£80
Fix a boiler fault code near Grimsby£74
Fix a boiler fault code near Wallasey£86
Fix a boiler fault code near Stockton-on-Tees£84
Fix a boiler fault code near Weston-super-Mare£78
Fix a boiler fault code near High Wycombe£114
Fix a boiler fault code near Ashford£98
Fix a boiler fault code near Redditch£84
Fix a boiler fault code near Wigan£84
Fix a boiler fault code near Scunthorpe£74
Fix a boiler fault code near Bury£82
Fix a boiler fault code near Paisley£88
Fix a boiler fault code near Bracknell£118
Fix a boiler fault code near Burnley£76
Fix a boiler fault code near Rugby£88
Fix a boiler fault code near Guildford£116
Fix a boiler fault code near Carlisle£62
Fix a boiler fault code near Chatham£96
Fix a boiler fault code near East Kilbride£86
Fix a boiler fault code near Newcastle-under-Lyme£82
Fix a boiler fault code near Chesterfield£80
Fix a boiler fault code near Burton upon Trent£80
Fix a boiler fault code near Tamworth£84
Fix a boiler fault code near Shrewsbury£82
Fix a boiler fault code near Woking£116
Fix a boiler fault code near St Albans£114
Fix a boiler fault code near Harrogate£78
Fix a boiler fault code near Crewe£82
Fix a boiler fault code near South Shields£90
Fix a boiler fault code near Craigavon£60
Fix a boiler fault code near Stafford£82
Fix a boiler fault code near Rotherham£80
Fix a boiler fault code near Barnsley£78
Fix a boiler fault code near Lowestoft£88
Fix a boiler fault code near Walsall£84
Fix a boiler fault code near Gosport£90
Fix a boiler fault code near Dartford£114
Fix a boiler fault code near Bognor Regis£94
Fix a boiler fault code near Corby£88
Fix a boiler fault code near Paignton£78
Fix a boiler fault code near Maidenhead£116
Fix a boiler fault code near Rochester£98
Fix a boiler fault code near Ellesmere Port£86
Fix a boiler fault code near Loughborough£82
Fix a boiler fault code near Dudley£84
Fix a boiler fault code near Bangor£68
Fix a boiler fault code near Dewsbury£78
Fix a boiler fault code near Mansfield£80
Fix a boiler fault code near Margate£92
Fix a boiler fault code near Kettering£94
Fix a boiler fault code near Cannock£84
Fix a boiler fault code near Sale£84
Fix a boiler fault code near Taunton£70
Fix a boiler fault code near Runcorn£88
Fix a boiler fault code near Farnborough£118
Fix a boiler fault code near Tynemouth£90
Fix a boiler fault code near Hereford£162
Fix a boiler fault code near Halesowen£84
Fix a boiler fault code near Widnes£86
Fix a boiler fault code near Huyton with Roby£86
Fix a boiler fault code near Scarborough£72
Fix a boiler fault code near Gravesend£102
Fix a boiler fault code near Bebington£86
Fix a boiler fault code near Kidderminster£84
Fix a boiler fault code near Stourbridge£84
Fix a boiler fault code near Barry£78
Fix a boiler fault code near Smethwick£84
Fix a boiler fault code near Dunfermline£92
Fix a boiler fault code near Livingston£90
Fix a boiler fault code near Weymouth£78
Fix a boiler fault code near Brentwood£102
Fix a boiler fault code near Barrow-in-Furness£104
Fix a boiler fault code near Hamilton£84
Fix a boiler fault code near Canterbury£94
Fix a boiler fault code near Wellingborough£94
Fix a boiler fault code near Sittingbourne£94
Fix a boiler fault code near Macclesfield£82
Fix a boiler fault code near Bootle£86
Fix a boiler fault code near Carlton£80
Fix a boiler fault code near Esher£120
Fix a boiler fault code near Clacton-on-Sea£94
Fix a boiler fault code near Lancaster£80
Fix a boiler fault code near Beeston£78
Fix a boiler fault code near Banbury£98
Fix a boiler fault code near Torquay£78
Fix a boiler fault code near Folkestone£98
Fix a boiler fault code near Kingswinford£86
Fix a boiler fault code near Bloxwich£84
Fix a boiler fault code near Bridgend£76
Fix a boiler fault code near Welwyn Garden City£112
Fix a boiler fault code near Lisburn£68
Fix a boiler fault code near Leamington Spa£88
Fix a boiler fault code near Washington£88
Fix a boiler fault code near Tunbridge Wells£106
Fix a boiler fault code near Kirkcaldy£88
Fix a boiler fault code near Hinckley£84
Fix a boiler fault code near Durham£88
Fix a boiler fault code near Cumbernauld£90
Fix a boiler fault code near Wokingham£118
Fix a boiler fault code near Horsham£110
Fix a boiler fault code near Crosby£86
Fix a boiler fault code near Yeovil£70
Fix a boiler fault code near Thundersley£96
Fix a boiler fault code near Altrincham£86
Fix a boiler fault code near Willenhall£84
Fix a boiler fault code near Christchurch£88
Fix a boiler fault code near Keighley£78