In This Guide
Introduction
The EA 227 is one of the more straightforward fault codes a Worcester Bosch boiler can display, because it tells you exactly what has happened: the boiler tried to light and failed. What it does not tell you is why, and the reason matters, because some causes are a five-minute homeowner fix and others require a qualified engineer with replacement parts.
This guide explains the EA 227 code, works through each cause in order of likelihood, tells you what you can safely check yourself, and is clear about where the boundary is between a homeowner check and a Gas Safe job.
What Does the Worcester EA 227 Fault Code Mean?
The EA prefix on Worcester Bosch boilers indicates an ignition fault. The number 227 specifies the type: no ignition, meaning the burner failed to establish a flame within the permitted number of attempts. After three failed ignition sequences the boiler enters lockout mode and displays EA 227, stopping further ignition attempts until manually reset.
This is a safety feature, not a malfunction in itself. The boiler is designed to stop trying to ignite if it cannot confirm a stable flame, because continuing to introduce gas without successful ignition creates a hazard.
The EA 227 appears across the Worcester Bosch Greenstar range, including:
- Greenstar 25i, 30i, 40i
- Greenstar CDi Compact
- Greenstar i System
- Greenstar Si Compact
- Greenstar 8000 Style and Life series
- Greenstar 4000
On older models without a digital display, the equivalent fault may be indicated by a flashing light sequence rather than a code. Refer to your installation manual if you are unsure.
Causes of the EA 227 Fault: Most Likely First
1. Frozen or Blocked Condensate Pipe
This is the most common cause of EA 227 in winter, particularly in London properties where the condensate pipe runs externally. The condensate pipe carries acidic wastewater from the boiler to the drain. When it freezes, the boiler cannot discharge condensate and the ignition sequence fails.
How to check: Locate the condensate pipe, typically a white plastic pipe around 22mm in diameter running from the base of the boiler to an external wall or internal soil stack. If it runs outside, feel along its length for a hard frozen section.
What to do: Thaw with warm water poured along the pipe from the outlet end back toward the boiler. Do not use boiling water. Once clear, reset the boiler. If it lights, insulate the pipe with foam lagging to prevent a recurrence.
2. Gas Supply Interruption
If there is no gas reaching the boiler, it cannot ignite regardless of the condition of its components.
How to check: Test another gas appliance in the property, such as the hob or a gas fire. If these are also not working, the issue is with the gas supply rather than the boiler. Check that the gas isolation valve on the supply pipe to the boiler is in the open position, which means the handle is parallel to the pipe, not perpendicular to it.
What to do: If other gas appliances are also not working, contact your gas supplier. If the isolation valve is closed, open it and reset the boiler.
3. Faulty Ignition Electrode
The ignition electrode creates the spark that lights the gas burner. Over time the electrode tip wears, carbon deposits build up on the ceramic insulator, or the electrode position shifts, all of which reduce or eliminate the spark. This is one of the most common component failures on Worcester Bosch boilers after several years of operation.
How to check: You cannot inspect the ignition electrode safely without opening the boiler casing. If the gas supply is confirmed and the condensate pipe is clear, and the EA 227 returns after reset, a faulty electrode is the most likely cause.
What to do: Call a Gas Safe registered engineer. Ignition electrode replacement is a straightforward repair on Greenstar models and is typically completed within an hour.
4. Failed Flame Sensor
The flame sensor, also called the flame sensing electrode, confirms to the PCB that a flame has been established after ignition. If the sensor is contaminated with carbon deposits or has failed, the boiler ignites but the PCB receives no confirmation signal, so it shuts down the gas valve and logs EA 227 as a safety response.
This can sometimes present as a boiler that appears to fire briefly then immediately shuts down, rather than one that fails to ignite at all. Both trigger the EA 227 code after three attempts.
What to do: Flame sensor diagnosis and replacement is an engineer job. The sensor is located inside the combustion chamber and cannot be safely accessed or tested without proper equipment.
5. Faulty Gas Valve
The gas valve controls the flow of gas to the burner during the ignition sequence. If the valve fails to open fully, opens too slowly, or sticks intermittently, insufficient gas reaches the burner during the ignition window and the flame either does not establish or immediately dies, triggering EA 227. A faulty gas valve is less common than electrode or sensor failure but is more likely on boilers over ten years old or on properties where the gas supply pressure fluctuates.
This fault is not diagnosable by the homeowner. There are no external signs that distinguish a gas valve fault from an electrode or sensor fault. An engineer will test the valve’s electrical operation and measure gas flow during the ignition sequence to confirm whether the valve is the cause.
What to do: Gas valve replacement is a Gas Safe engineer job. The valve is a gas-carrying component and must not be tampered with by anyone who is not Gas Safe registered.
6. PCB Fault
The PCB (printed circuit board) controls the ignition sequence, monitors the flame sensor signal, and manages the gas valve. A PCB that has partially failed may be unable to initiate the ignition sequence, unable to interpret the flame sensor signal, or unable to operate the gas valve correctly, all of which produce an EA 227.
PCB faults are the least common cause of EA 227 and should only be considered after an engineer has tested and ruled out the ignition electrode, flame sensor and gas valve.
What to do: PCB diagnosis is an engineer job. Replacement PCBs for Worcester Greenstar models are widely available and the repair is typically completed in one visit.
What You Can Safely Do Before Calling an Engineer
Check | How to Do It | Safe for Homeowner? |
Confirm gas supply is live | Test hob or gas fire | Yes |
Check isolation valve is open | Handle parallel to pipe = open | Yes |
Inspect condensate pipe for freezing | Feel along external pipe for frozen section | Yes |
Thaw frozen condensate pipe | Warm water along pipe from outlet end | Yes |
Reset the boiler once | Front panel reset button or dial | Yes |
Inspect ignition electrode | Requires opening boiler casing | No |
Test or replace flame sensor | Inside combustion chamber | No |
Test or replace gas valve | Gas component – Gas Safe only | No |
Diagnose or replace PCB | Mains voltage component | No |
If the EA 227 returns after you have confirmed the gas supply is live and the condensate pipe is clear, the cause is inside the boiler and requires a Gas Safe registered engineer.
How to Reset a Worcester Bosch Boiler After EA 227
On most Greenstar models the reset procedure is as follows:
Greenstar i and Si models: Press and hold the reset button on the front panel for approximately three seconds until the display changes. The button is typically marked with a flame symbol.
Greenstar CDi Compact: Turn the mode selector dial to the reset position, hold for three seconds, then return to the operating position.
Touch screen models: Navigate to the fault screen and select reset from the menu.
After reset, the boiler will attempt the ignition sequence again. If it lights and stays running, the fault was transient. If EA 227 returns within the first few minutes of operation, the underlying cause has not been resolved and further attempts to reset will not fix it.
Do not reset the boiler more than once or twice without identifying the cause. Repeated failed ignition attempts introduce unburned gas into the boiler casing, which is a safety risk.
How 0800 Homefix Diagnoses EA 227
When our engineers attend an EA 227 call, the diagnostic process is systematic rather than speculative. We do not replace parts until we have confirmed which component has failed.
Step 1 – Gas supply and pressure: Confirm the supply is live and that gas pressure at the boiler is within the correct operating range. Low gas pressure from the mains can cause intermittent ignition failure even when the supply is not fully interrupted.
Step 2 – Condensate trap and pipe: Inspect the condensate trap inside the boiler for blockage and check the external pipe for freezing or obstruction. A blocked trap causes the same lockout as a frozen pipe.
Step 3 – Ignition electrode: Test the electrode for spark quality, check the ceramic insulator for cracks or carbon tracking, and verify the electrode gap and positioning against the manufacturer’s specification.
Step 4 – Flame sensor: Check the flame sensing electrode for carbon contamination and test its electrical continuity. A contaminated sensor that cannot send a clean signal to the PCB is one of the most common causes of EA 227 on boilers over five years old.
Step 5 – Gas valve: Test the gas valve for correct opening, modulation and closure. A valve that opens too slowly or incompletely prevents sufficient gas from reaching the burner during the ignition window.
Step 6 – PCB: Verify PCB output signals to the ignition circuit and check for signs of moisture ingress, burn marks or component failure.
In most cases the fault is resolved at Step 3 or Step 4. We carry replacement parts for Worcester Bosch Greenstar models on our vans, so the repair is completed on the first visit in the majority of cases.
Preventing EA 227 Faults
Most EA 227 faults are preventable. An annual service by a Gas Safe registered engineer includes cleaning and testing the ignition electrode and flame sensor, inspecting and clearing the condensate trap, checking gas supply pressure, and identifying early signs of component deterioration. The majority of EA 227 callouts we attend in winter are on boilers that have not been serviced in the previous twelve months.
For properties where the condensate pipe runs externally, fitting foam pipe insulation before the cold season is a simple and inexpensive measure that prevents the most common cause of EA 227.
Worcester Bosch’s standard warranty is two years, extendable to seven or ten years when installed and annually serviced by a Worcester Bosch accredited installer. Details on warranty terms and registered installers are available at worcester-bosch.co.uk.
To verify that any engineer attending your property is legally registered to carry out gas work, check their Gas Safe registration at gassaferegister.co.uk.
Book an annual Worcester Bosch boiler service to keep the ignition system clean and catch component wear before it causes a lockout.
Frequently Asked Questions About the Worcester EA 227 Fault
What does EA 227 mean on a Worcester boiler?
EA 227 is a no ignition fault code. It means the boiler attempted to light the gas burner three times, failed to establish a confirmed flame on any attempt, and has locked out as a safety measure. The boiler will not attempt to fire again until manually reset. The fault can be caused by a frozen condensate pipe, interrupted gas supply, faulty ignition electrode, failed flame sensor, or PCB fault. Check the gas supply and condensate pipe first. If the fault returns after a reset, call a Gas Safe registered engineer.
Can I fix the EA 227 fault myself?
The checks you can safely carry out yourself are confirming the gas supply is live, checking the condensate pipe for freezing, and resetting the boiler once. If any of these checks resolves the fault and it does not return, no further action is needed. If EA 227 returns after these checks, the fault is inside the boiler and requires a Gas Safe registered engineer. Do not open the boiler casing or attempt to inspect or replace ignition components yourself.
Is the EA 227 fault dangerous?
The EA 227 lockout is itself a safety response, not a dangerous condition. The boiler has stopped operating to prevent the risks associated with repeated failed ignition attempts. However, the underlying cause should be diagnosed and repaired by a qualified engineer rather than bypassed through repeated resets. Continually resetting without fixing the fault introduces unburned gas into the boiler casing over time.
How long does it take to fix EA 227?
In most cases, one visit. If the cause is a frozen condensate pipe, the fix takes under thirty minutes including thawing and reset. If the ignition electrode or flame sensor requires replacement, the repair typically takes one to two hours. PCB replacement takes slightly longer. Our engineers carry Worcester Bosch replacement parts on their vans, so parts availability rarely causes a return visit.
Why does my Worcester boiler keep showing EA 227 after reset?
If EA 227 returns consistently after reset, the underlying component fault has not been resolved. A single successful reset after thawing a condensate pipe is expected. An EA 227 that returns within minutes or hours of reset without a clear transient cause, such as freezing, indicates a component fault at the electrode, flame sensor, gas valve or PCB. Repeated resets will not fix it and are not advisable as a management strategy.
Does EA 227 mean I need a new boiler?
Not usually. EA 227 is almost always a repairable fault. Ignition electrode and flame sensor replacements are among the most common and straightforward boiler repairs, and the parts are inexpensive relative to boiler replacement. A PCB replacement is more costly but still significantly cheaper than a new boiler in most cases. If your Worcester Bosch boiler is more than fifteen years old and has had multiple faults in the same season, an engineer can give you an honest comparison of repair versus replacement costs.
Can EA 227 appear in summer?
Yes, though it is less common. In summer the frozen condensate pipe cause is ruled out, making an ignition electrode, flame sensor or gas supply issue more likely. Intermittent EA 227 faults in warmer months are often caused by component deterioration that has been developing gradually and has reached the point of failure. An annual service in autumn typically catches these issues before they cause a lockout.
When to Call 0800 Homefix
If the EA 227 persists after confirming your gas supply and checking the condensate pipe, our Gas Safe registered engineers cover London and the home counties 7 days a week. We carry Worcester Bosch parts on our vans, complete most EA 227 repairs on the first visit, and give you a fixed price before any work begins. No call-out fee.
Editorial Note
This guide is intended as a general homeowner reference. All work involving gas components must be carried out by a Gas Safe registered engineer under the Gas Safety (Installation and Use) Regulations 1998. If you smell gas at any point, leave the property immediately and call the National Gas Emergency Service on 0800 111 999.
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Editorial note: This article is intended as a general homeowner guide. All plumbing work on supply pipes should be carried out by a qualified, WaterSafe-registered plumber. If you suspect a gas leak, leave the property immediately and call the National Gas Emergency Service on 0800 111 999.
