Our boilers are an appliance in the home we do not give a second thought to, until they stop working and we are left with no heat and /or no hot water! When a boiler stops working or is chugging on with a fault, the boiler will display a fault code to signal to you 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 for 2023 available in the UK;
These are the boiler brands we will focus on when discussing and helping identify boiler fault codes most often experienced by homeowners.
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.
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
Replacing a faulty fan
£80 + £230 for the fan
Replacing a burnt-out pump
£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
Repressurising the system and spending time checking for signs of leaks
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.
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:
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
|Cost to replace a hot water immersion heater||£275|
|Cost to fit underfloor heating||£250|
|Cost to service a gas fire||£150|
|Cost to replace a vented hot water cylinder||£330|
|Cost to replace a central heating pump||£95|
|Cost to replace a heating programmer||£180|
|Cost to powerflush a central heating system||£500 Visit|
|Cost to install heating oil storage tank||£1250|
|Cost to replace an oil boiler||£1330|
|New combi or system boiler installation – like for like replacement||£500|
|Cost to move and relocate a boiler||£830|
|Cheap boiler insurance||£10.00 per month|
|Cost to install skirting board heating||£990|
|Cost to install an LPG boiler||£1190|
|Cost to install hydrogen boiler||£1350|
|Cost to install a gas fire||£350|
|Cost to install a chimney liner||£575|
|Cost to install biomass boiler||£1430|
|Cost to install a ground source heat pump||£3750|
|Cheap gas||£110.00 per month|
|Cost to fix a boiler fault error code||£85|
|Cost to replace an unvented hot water cylinder, e.g., Megaflo||£305|
|Cost to fit thermostatic radiator valves (TRVs)||£94|
|Cost to fit smart heating controls||£100|
|Cost to fit a magnetic filter for boiler||£113|
|Cost to fit a heated towel rail||£75|
|Cost to fit a radiator||£80|
|Cost to install a gas cooker or hob||£190|
|Boiler service cost||£90|
|Boiler repair costs (e.g. pump, diverter valve or heat exchanger)||£333|
|Cost to install an air source heat pump||£556|
|Replacement of a vented system||£580|