Worcester Bosch EA 261 Fault Code: Causes, Fixes & Repair Costs
What does the Worcester Bosch EA 261 fault code mean?
The EA 261 code tells you that your Worcester Bosch boiler has locked out after failing to establish or confirm a stable flame during its ignition sequence. There are two closely related causes the boiler's electronics flag under this code: an ignition timing error — meaning the gas did not successfully light within the permitted window — and a potential fault with the Heat Control Module (HCM), also known as the burner control unit. In both cases, the boiler's PCB has not received confirmation of a successful ignition attempt and has shut the appliance down as a safety precaution to prevent unburned gas from accumulating. The result is a complete loss of both central heating and hot water until the underlying problem is identified and resolved. Because this code sits within the EA (ignition lockout) family, some engineers may also encounter related EA sub-codes on Worcester Bosch appliances — for example EA 227 (flame signal lost during operation) or EA 338 (repeated ignition failures causing a hard lockout) — which share a broadly similar diagnostic pathway but may point more specifically to the flame-sensing circuit or gas pressure issues rather than the HCM itself.
General guidance only — not a substitute for professional advice, and not certified by a Gas Safe engineer. Always have your specific appliance assessed by a qualified professional. Any gas work must be carried out by a Gas Safe registered engineer. If you smell gas or suspect carbon monoxide, leave the property and call the National Gas Emergency line on 0800 111 999.
Common causes
- Faulty or degraded ignition electrodes Common
The ignition electrode creates the spark that lights the gas, while the flame-sensing electrode confirms the burner is alight. Over time these components corrode, accumulate carbon deposits, or drift out of their correct position. When that happens, the PCB either cannot initiate a spark or cannot detect the resulting flame, triggering the EA 261 lockout. This is the single most common cause of this particular fault code.
- Gas supply interruption or insufficient gas pressure Common
If the gas supply to your home has been interrupted — for instance due to a network outage, an unpaid prepayment meter, or a meter fault — the boiler will attempt to ignite against an empty pipe and fail every time. Low working gas pressure is a related but distinct issue: even with gas present, pressure that falls below the boiler's minimum operating threshold will produce the same result. Gas pressure problems beyond the meter are not something a homeowner can investigate safely.
- Heat Control Module (HCM) or PCB fault Sometimes
The HCM, sometimes called the burner control unit, governs the entire ignition and combustion sequence. If this module has developed a fault — or if a replacement HCM of the wrong specification has been fitted during a previous repair — the boiler will consistently fail the ignition check and lock out with EA 261. The main PCB, which oversees all boiler operations, can produce the same symptom if it is failing to send or interpret signals correctly.
- Faulty gas valve Sometimes
The gas valve controls the flow of gas to the burner. A valve that is sticking, failing to open fully, or not responding to the PCB's commands will starve the burner of fuel and cause an ignition lockout. Gas valve faults are inherently a Gas Safe engineer task — do not attempt to inspect or adjust the valve yourself.
- Frozen or blocked condensate pipe Sometimes
During cold snaps, the plastic condensate pipe that runs outside the property can freeze solid, backing up condensate into the boiler and triggering a lockout. While this more typically produces a specific condensate fault code, it can in some circumstances contribute to an EA lockout, particularly if the fan is also affected. You can safely attempt to thaw the visible external section of the pipe with warm (not boiling) water.
- Blocked or restricted flue Rare
The flue removes combustion gases from the boiler. A partial or complete blockage — caused by a bird's nest, debris, or ice in very cold weather — can disrupt the combustion conditions to the point where ignition fails or the boiler locks out for safety. A blocked flue is a Gas Safe task to clear and inspect.
- Faulty fan Rare
The fan must reach the correct speed before the boiler is permitted to attempt ignition, ensuring combustion gases can be expelled safely. A fan that is worn, seized, or failing intermittently will prevent the ignition sequence from starting and can contribute to an EA lockout. Fan faults may occasionally appear alongside a separate C6 fault code on the display.
How to fix it
- Check that your gas supply is working DIY safe
Turn on a gas hob burner or another gas appliance in your home. If it lights normally, your supply is active and you can move on to the next step. If you have a prepayment meter, confirm there is sufficient credit. If gas is not reaching any appliance, contact your gas supplier — do not attempt to investigate the meter or supply pipework yourself.
- Check for a frozen condensate pipe DIY safe
If the outside temperature has been at or below freezing, locate the plastic condensate pipe — usually a white or grey 32 mm or 40 mm pipe exiting through an outside wall near the boiler. If it appears frozen or you can see ice, gently pour warm (not boiling) water along the pipe to thaw it. Work from the boiler end towards the drain. Once thawed, proceed to reset the boiler.
- Reset the boiler DIY safe
With the gas supply confirmed as active, attempt a single reset. On most Worcester Bosch models, turn the central control dial to the reset symbol and hold for approximately three seconds, then release. Allow the boiler to complete its ignition sequence. If it fires up and the EA 261 clears, monitor the boiler over the next few hours. If the code returns, do not reset more than two or three times in total — repeated resets without fixing the root cause can mask a developing fault and are not a solution.
- If the fault persists, stop resetting and call a Gas Safe registered engineer Gas Safe engineer
A returning or persistent EA 261 points to a component fault — most likely the ignition electrodes, HCM, gas valve, or PCB — that requires qualified diagnosis and repair. A Gas Safe engineer will test gas pressure at the boiler, inspect and test the ignition and flame-sensing electrodes, assess the HCM and PCB for faults, check the fan operation and flue integrity, and carry out any necessary replacement work. Do not continue resetting the boiler in the hope the fault clears on its own.
Parts you may need
- Ignition electrode assembly · from £45
- Flame-sensing electrode · from £35
- Gas valve · from £120
- Fan (flue fan / air pressure assembly) · from £95
- Heat Control Module (HCM / burner control unit) · from £180
- PCB (main printed circuit board) · from £220
The exact spare depends on your boiler's GC number (on the data badge). Check this against the part before buying.
Typical repair cost
Expect to pay roughly £120–£350, depending on the underlying cause.
Frequently asked questions
Can I fix Worcester Bosch EA 261 myself?
The only steps a homeowner can safely carry out are confirming the gas supply is on, thawing a frozen condensate pipe, and resetting the boiler once or twice. Any work on the ignition electrodes, gas valve, HCM, PCB, or flue must be carried out by a Gas Safe registered engineer. Attempting gas-related repairs without registration is both dangerous and illegal under UK law.
How much does it cost to fix a Worcester Bosch EA 261 fault?
For the most common causes, most people pay somewhere between £120 and £350 including parts and labour. Replacing ignition electrodes typically falls at the lower end of this range, while a gas valve swap usually sits in the middle. PCB replacement is the outlier — parts alone can cost £200 to £300, pushing the total bill to £400 or more — but this is a less frequent cause of EA 261 and would normally only be considered after other components have been ruled out.
What is the difference between EA 261 and other EA fault codes such as EA 227 on a Worcester Bosch boiler?
All EA codes on Worcester Bosch boilers relate to ignition or flame-detection failure, but the numeric sub-code points to the specific point in the sequence where the fault occurred. EA 261 indicates either an ignition timing error or a suspected HCM fault. EA 227 typically means the flame signal was lost after the burner had successfully lit — suggesting more of a flame-sensing or gas pressure instability issue. EA 338 usually reflects repeated ignition failures leading to a hard lockout. Your engineer will use the full code displayed on your boiler to guide their diagnosis, so always note the complete code including the number.
My Worcester Bosch keeps showing EA 261 after I reset it — should I keep resetting it?
No. One or two resets are reasonable to rule out a one-off glitch, but if the EA 261 code returns consistently after resetting, there is an underlying component fault that resetting will not fix. Continuing to reset the boiler repeatedly can mask the problem and, in a worst case, poses a safety risk. At this point you should stop resetting and arrange for a Gas Safe engineer to carry out a proper diagnosis.
Is it worth repairing a Worcester Bosch showing EA 261, or should I replace the boiler?
If the fault is caused by ignition electrodes or a gas valve, repair is almost always the sensible choice and the cost is manageable. If your boiler is more than 12 to 15 years old and the engineer identifies a failed PCB or HCM as the cause, it is worth getting a replacement quote at the same time. Newer Worcester Bosch models typically come with a 10 or 12-year manufacturer warranty when installed by an accredited installer, which can make replacement more cost-effective over the long term if your current boiler is ageing and experiencing recurring faults.