Quick answer: The EA fault code means your Worcester Bosch boiler tried to ignite and no flame was detected, or the flame signal was lost during operation. After several failed attempts, usually four, the boiler locks out for safety. In Scotland, the single most common cause between November and March is a frozen condensate pipe, and that’s something you can often sort yourself in twenty minutes.
Written by the engineering team at Edinburgh Boiler Company, Scotland’s number one boiler installer. EA is the code that fills our phone lines during a cold snap, and a good share of those calls end with the customer fixing it themselves while we’re on the line.
The fault is usually followed by a code which we would also need, these are:
What does EA mean on a Worcester boiler?
EA means no flame. The boiler ran through its normal start-up sequence, opened the gas valve, sparked the ignition electrode, and then looked for a flame signal from the sensing electrode. It didn’t find one. It tried again. After a set number of failed attempts, the control board stops trying and locks out.
That lockout is the boiler protecting you. A boiler that kept opening the gas valve without establishing a flame would be releasing unburnt gas into the combustion chamber, which is exactly what no gas appliance should ever do.
The useful thing about EA is that it doesn’t tell you why there’s no flame. It only tells you there isn’t one. That leaves a short list of possibilities, and they range from trivial to expensive.
What causes an EA fault on a Worcester Greenstar?
| Cause | How common in Scotland | Homeowner fixable? |
|---|---|---|
| Frozen condensate pipe | Very common in winter | Yes |
| No gas supply (prepay meter, closed valve, supply issue) | Common | Yes |
| Blocked condensate trap or pipe (not frozen) | Common | No |
| Worn or dirty ignition and flame-sensing electrodes | Common | No |
| Faulty gas valve | Occasional | No |
| Blocked flue or air intake | Occasional | No |
| PCB fault | Less common | No |
Two of those seven are things you can safely deal with yourself, and between them they account for a large share of winter EA call-outs. Start there.
Why do frozen condensate pipes cause so many EA faults in Scotland?
Because Scotland gets colder for longer than most of the UK, and because a great many Scottish condensate pipes run outside where they shouldn’t. Every condensing boiler produces acidic wastewater that has to drain away. Ideally that pipe runs internally to a soil stack or waste pipe. In reality, particularly in tenement flats, conversions and older retrofits, it very often runs out through the wall to a gully or drain.
When the temperature drops below about minus one and stays there, water sitting in that external condensate pipe freezes. The blockage backs the condensate up into the boiler, the pressure switch or trap detects it, and the boiler refuses to fire. On many Worcester models the resulting code is EA.
You’ll know it’s likely to be this if:
- The fault appeared overnight during a cold spell.
- You can hear a gurgling or bubbling from inside the boiler when it tries to fire.
- The white plastic pipe running outside your wall feels ice-cold and solid.
- Your neighbours with the same setup are having the same problem.
Read more for older boilers about the Worcester Bosch blue light flashing error codes for more information on older Greenstar models
What can I safely check myself?
Four things, in this order. None of them involve opening the boiler.
1. Check you actually have gas. Try your hob or another gas appliance. If nothing gas-fired works, the boiler isn’t the problem. Check your prepayment meter has credit, because an empty meter is one of the most common EA causes we attend and it’s a wasted call-out fee. If your credit is fine and no appliance works, contact your supplier.
2. Check the gas isolation valve. There’s a valve on the gas pipe below the boiler, usually with a yellow or brass handle. Open means the handle lines up with the pipe. Across means closed. It’s rarely the answer, but it takes five seconds to rule out and we have genuinely found this after kitchen fitting work.
3. Thaw the condensate pipe if it’s frozen. Find the white or grey plastic pipe, usually 22mm or 32mm, running from the boiler through the external wall. Pour warm water along its length, concentrating on the exposed section and any bend or the open end. Warm, not boiling. Boiling water can crack cold plastic and split the pipe, which turns a free fix into a repair. A hot water bottle or a wheat bag held against the pipe also works and is gentler.
4. Reset the boiler, once. Hold the reset button for three to five seconds. Give it a minute to run through its sequence. If it fires and stays running, you’re done.
If you smell gas at any point: leave the property, then call the National Gas Emergency Service on 0800 111 999 from outside. If you’re on LPG, which covers a lot of rural Scotland off the mains grid, call your supplier’s emergency number instead.
What must I not do?
- Don’t remove the boiler casing. Everything past that point is gas and mains electrical work, and it’s illegal without Gas Safe registration.
- Don’t keep resetting. More than one or two resets on an EA fault means you’re repeatedly asking a boiler that can’t establish a flame to open its gas valve again.
- Don’t use boiling water on the condensate pipe.
- Don’t climb on anything to reach a flue. Checking a flue terminal is fine from the ground. It isn’t worth a ladder in Scottish weather.
When should I call a Gas Safe engineer?
Call as soon as the fault returns after you’ve confirmed the gas supply and dealt with any frozen condensate. At that point the remaining causes are all internal: electrodes, gas valve, flue, or PCB. Those need proper diagnosis with a flue gas analyser and a manometer, not guesswork.
Call immediately, without trying anything, if you smell gas, see scorching or staining around the boiler, or hear a loud bang when it attempts to light.
What will the engineer do?
- Gas tightness test and working gas pressure check at the meter and at the appliance.
- Inspection of the ignition and flame-sensing electrodes, checking the gap, the tip condition and the ceramic insulator for cracks.
- Condensate trap strip and clean.
- Flue and air intake inspection for blockage or damage.
- Gas valve testing.
- Combustion analysis after any repair, with the readings recorded on your paperwork.
Electrodes are the most common paid repair on this fault, and they’re one of the cheapest. Worth ruling in early.
How much does it cost to fix an EA fault in Scotland?
Between nothing and about £650, depending on where the fault turns out to be. Guide prices below are for Scotland in 2026, parts fitted, by a Gas Safe registered engineer.
| Fix | Guide cost | Time on site |
|---|---|---|
| Thawing a frozen condensate pipe yourself | Free | 20 mins |
| Call-out to thaw and lag a condensate pipe | £80–£160 | 30–60 mins |
| Diagnostic visit | £70–£130 | 45–90 mins |
| Ignition and flame-sensing electrode set | £140–£230 | 1–1.5 hours |
| Condensate trap clean or replacement | £110–£190 | 1 hour |
| Flue clearing or terminal replacement | £120–£300 | 1–2 hours, more if access is difficult |
| Gas valve replacement | £320–£550 | 2–3 hours |
| PCB replacement | £350–£650 | 2–3 hours |
Access affects flue work more than anything else. A flue terminating three floors up on a tenement gable is a different job from one on a bungalow wall, and any quote should say clearly whether access equipment is included.
How do I stop EA happening again?
Lag the condensate pipe. This is the highest-value thing on the list for a Scottish property. Waterproof pipe insulation costs very little and prevents the whole problem. Make sure the lagging is rated for external use, because standard foam sleeving degrades quickly in our weather.
Get the pipe re-routed if it’s badly installed. A long external run, a pipe with a sag holding standing water, or one that terminates in an exposed spot will keep freezing no matter how well you lag it. Rerouting internally to a soil stack, or increasing the pipe diameter to 32mm on the external section, solves it permanently.
Keep the heating ticking over in very cold weather rather than switching it off entirely while you’re away. A boiler that fires occasionally keeps warm water moving through the condensate route.
Book the annual service. Electrodes get inspected and cleaned, the condensate trap gets checked, and gas pressures get verified. Most EA faults that aren’t weather-related show warning signs at a service first.
Sort recurring ignition faults promptly. A boiler that occasionally needs a reset to light is telling you the electrodes are on their way out.
What’s the Difference Between the Worcester EA and A1 Codes?
EA is an ignition or flame-loss fault — the burner isn’t lighting, or isn’t staying lit. The Worcester A1 fault code is unrelated: it points to the pump, whether that’s a seized pump, air trapped in the system, or one running dry. Both can leave you without heat, but the fix is completely different.
The bottom line
EA means no flame, and in a Scottish winter that most often means a frozen condensate pipe rather than a broken boiler. Check your gas supply, thaw the pipe with warm water, reset once. If it comes back after that, stop and book a Gas Safe registered engineer, because the remaining causes are all inside the casing.
Boiler still locking out? Edinburgh Boiler Company covers Edinburgh, the Lothians and central Scotland with Gas Safe registered engineers, full combustion testing on every gas repair, and written pricing before work starts. Get in touch and we’ll get you warm again.
This guide is general advice. Refer to your specific Worcester Bosch model’s user manual for reset instructions, and never remove the boiler casing. Gas work must be carried out by a Gas Safe registered engineer. If you smell gas, leave the property and call 0800 111 999, or your LPG supplier’s emergency line if you’re off the mains gas grid.
