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Why Is My Worcester Boiler Flashing Blue Light? And How To Fix It


Is your Worcester boiler flashing blue light? Sorry to break it to you, but there is something wrong with your boiler. However, there is no need to worry. It’s not the end of your unit. Usually, there’s an error code that accompanies the light. A certified gas engineer should be able to interpret it and fix the problem.

“The Error Code EA” is the most common to accompany the flashing blue light in Worcester Bosch boilers. Your boiler will display the code if it senses that gas isn’t being supplied to the unit. There are several causes for gas supply issues like:

  • Flue blockages.
  • Condensate pipe blockages.
  • A faulty ignition electrode.
  • A faulty flame sensor.
  • Gas leaks.
  • Low gas pressure.
  • Low boiler pressure

But before you jump to any conclusions, we advise you to check and confirm if other gas appliances in your home are working. If they are working well, then there is no problem with your mains gas supply. Instead, your boiler has an issue.

Boiler repairs are risky. There’s no amount of DIY skills that can help you fix a gas boiler. You should immediately shut down your unit and contact a certified Gas Safe engineer.

What Does A Flashing Blue Light On A Worcester Boiler Mean?

  1. Flue blockages

Your gas boiler produces the gases in the course of its operations. Flues are specialized pipes responsible for redirecting waste gases away from your boiler. The gases are toxic and must also exit your home. It’s the main reason why your boiler will quickly display the Error Code EA before halting operations.

A certified engineer will check the flue pipes for damages and clogs. Specifically, the engineer will inspect the vertical flues that are more prone to leaves and debris blockages.

Most modern boilers come with flue guards to prevent blockages. If yours doesn’t have one, then the engineer will install it for you.

  1. Condensate pipe blockages

Condensate pipes are responsible for redirecting acidic wastewater away from the boiler. Just like waste gases, your boiler produces acidic water as a by-product of its operations.

All condensing boilers are equipped with condensate pipes. If your boiler was manufactured after 2005, then it’s likely to have condensate pipes.

Condensate pipes are most likely to fail during harsh winter spells. The cold has a habit of freezing pipes and creating blockages. If that’s the situation, you can solve the issue by pouring warm water over the frozen section.

It’s also important to note that condensate pipes can also fail in other weather conditions. As always, we advise you to call a professional if you’re not sure what is bugging your condensate system.

Speaking of external condensate pipes, the Heating and Hotwater Industry Council (HHIC) has issued new regulations against them. As of January 2021, all boiler condensate pipes should terminate internally into a soil stack. It’s a safety procedure that will protect condensate pipes from the effects of the winter season. Consult the engineer as to what is required to make the switch from external to internal condensate pipes.

  1. A faulty ignition electrode

The ignition electrode is a crucial component responsible for sparking boiler gas once it has been released into the combustion chamber. If the ignition electrode fails, your Worcester boiler will immediately display the Error Code EA accompanied by the flashing blue light. Additionally, it will also cease all operations.

Don’t worry. The boiler ceases all operations to protect you and the unit from further damage. If it doesn’t stop, boiler gas will continue accumulating in the combustion chamber and might trigger an explosion.

The gas engineer will test your boiler’s ignition electrode. If it’s faulty, a replacement will be necessary.

  1. Issues with the flame sensor

Most gas boilers, including Worcester Bosch boilers, are controlled by a Print Circuit Board. It’s like your boiler’s brain. If it doesn’t sense that a flame is ignited, it will immediately shut off the gas supply to prevent gas buildup. Afterwards, the blue light will start flashing and displaying the Error Code EA.

Likewise, the engineer will test the flame sensor to find out if it’s working correctly. Flame sensors are hard to fix. The engineer will most likely have to replace the component.

  1. Gas leaks

Gas leaks can also cause flame loss that will, in turn, trigger the Error Code EA, which will accompany the blue flashing light. Additionally, gas leaks can also cause the ignition electrode to fail. As a precautionary move, we advise you to frequently inspect your unit for gas leaks. They’re dangerous and can easily cause an explosion. If you smell even a slight leak, you should completely switch off your boiler, turn off the gas supply, evacuate the property, and contact a Gas Safe Engineer.

  1. Low gas supply pressure

Your boiler requires a steady gas supply at the right pressure. If the gas pressure is too low, it won’t be enough to sustain the flame needed to heat water. Once the flame goes missing, your gas boiler will quickly display an error code accompanied by the flashing blue light.

You might encounter this problem after upgrading your Worcester boiler unit. If you haven’t also upgraded the pipe system, the gas supply might not be enough to cater to the boiler’s requirements.

  1. Low boiler pressure

Boiler pressure is different from gas supply pressure. In this case, we are referring to the pressure of the hot water circulating inside your boiler. Unlike all the other causes, this one will cause the boiler to display Error Code E207.

Low boiler pressure isn’t a critical problem. You can even solve it. First, you need to check your boiler’s pressure gauge. The boiler pressure should be around 1.5 bar for the unit to operate successfully. If the reading is below 1 bar, your boiler is suffering from low pressure and needs to be repressurized.

Even though pressure loss is a natural problem that creeps in as the years go by, heating engineers are advised to inspect the boiler system for leaks.

Service mode

This one isn’t a problem. If you notice that the blue light is pulsing without displaying an error code, then your boiler is probably in service mode.

The engineers might have recently serviced the boiler and left it in that mode. Also, someone might have accidentally activated the service switch. In such a scenario, you’ll have to reset your Worcester boiler.

How to reset your Worcester boiler

Sometimes, all your boiler needs is a good reset for it to go back to normal. If you’re lucky, you might even save the money you’d have otherwise spent hiring a gas engineer. However, we strongly advise against resetting a boiler that is displaying an Error Code. If you’re not careful, things might worsen. Wait unit an engineer inspects the system and resets the boiler.

First, you’ll have to locate the “reset” button or setting. Worcester boilers come in many designs and models. As always, we advise you to confirm the location with the help of the user’s guide.

Once you’ve found the button, press it for three seconds, then release it to initiate the reset procedure. Other models have the “reset” setting on the temperature dial. Turn the dial until it reaches the “reset” mark. Hold it for three seconds, then turn it back to the initial setting.


The flashing blue light is usually a sign that something is wrong with your Worcester Bosch boiler. If the light is accompanied by an Error Code, you most definitely have a problem. Most of the time, it’s caused by flame loss related issues. Don’t attempt to fix it alone. Instead, contact a certified Gas Safe engineer.

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