Real 2026 London prices for the common repairs, what moves the number, and how to avoid overpaying.
The short answer
The Worcester Bosch EA error means the boiler failed to ignite or could not detect its flame, so it has locked out for safety. It is the most common Greenstar fault code. Check your gas supply and condensate pipe, reset once, and call a Gas Safe engineer if EA returns.
What the law requires
What does the EA code mean on a Worcester boiler?
EA (often shown as EA 227 or alongside a number on newer displays) is the Greenstar range’s ignition and flame-detection lockout, and it is comfortably the code London engineers see most on Britain’s best-selling boiler. The boiler ran its ignition sequence and either no flame appeared or the flame-sensing circuit could not confirm one, so the gas valve closed and the boiler stopped. As with every ignition lockout, the code is the safety system doing its job; the task is finding out why the flame failed, and the causes split cleanly into ones you can check and ones an engineer must.
Why do Greenstars throw EA in winter especially?
Because the number-one seasonal trigger has nothing to do with the burner. Greenstar condensate pipes, where they run outside to a drain, freeze in cold snaps; the blocked pipe backs condensate up into the boiler, the boiler senses it cannot drain safely, and ignition is refused. The first properly cold morning of the year produces EA codes across London by the hundred. If your EA arrived with the frost, walk outside and look at the white plastic pipe before you do anything else; our frozen condensate pipe guide covers the safe ten-minute thaw. The remaining causes are the classic ignition suspects: interrupted gas supply (meter credit, a partially closed valve, a street-level interruption), ageing ignition or flame-sense electrodes, a flue problem disturbing combustion, or, less often, the gas valve or control board.
How to reset a Worcester Bosch EA fault
Confirm other gas appliances work, and prepayment customers confirm the meter has credit. No gas at the hob means a supply issue, not a boiler issue.
In freezing weather, check the external condensate pipe and thaw it with warm water if it is iced; then continue.
Find the reset function: on most Greenstars a reset button or a dial position marked with a flame-reset symbol, depending on model. Hold or select it as your manual shows, typically for a few seconds.
Let the boiler complete a full ignition attempt without interruption.
If EA returns, leave it locked out and book a Gas Safe engineer. Repeated resets add nothing and prove nothing.
EA back again? Our Worcester Bosch specialists repair Greenstars across London daily and carry the common ignition parts on board. Call 020 3000 0000.
What will an engineer actually do?
A proper EA diagnosis works through the chain in order: confirm gas supply and working pressure at the appliance, inspect and test the ignition and flame-sense electrodes (the most common repair, and a quick one), check the condensate route end to end, examine the flue for blockage or recirculation, then test the gas valve and controls if everything upstream passes. The order matters because the cheap causes are also the frequent ones; a firm that quotes you a gas valve over the phone, unseen, is guessing at your expense. London costs run roughly: electrode replacement £120 to £240, condensate remedial work £95 to £180, flue investigation quoted on findings, gas valve £220 to £400, control board £300 to £500, always as a fixed quote after diagnosis.
Want a real number instead of a range? Describe the fault, get a fixed quote after diagnosis, and pay only what was quoted. No call-out fee across London.
Worcester Bosch EA, quick answers
Is the EA code dangerous?
The lockout is the safe state. Do not bypass it, do not keep resetting it, and if you ever smell gas call 0800 111 999 free before anything else.
Why does EA come back every few weeks?
Intermittent EA usually means a weakening electrode, a marginal condensate fall that partially blocks, or a flue issue that worsens in certain winds. Intermittent faults are exactly what diagnosis is for; note when it happens (cold mornings, windy days) and tell the engineer, because the pattern is half the answer.
Will a service prevent EA?
Often, yes. Electrode wear and condensate problems are precisely what an annual boiler service catches early.
Does F28 mean my boiler is finished?
Almost always; Worcester parts are plentiful and the platform is durable. Past twelve years with a major fault, ask for both sets of numbers, per our repair or replace guide.