Worcester boiler flashing a blue light

And What Can You Do About It

Have you noticed your Worcester boiler flashing a blue light and wondered what it means? Whether your heating has stopped working or you’re just being cautious, a flashing blue light on your boiler is something you shouldn’t ignore. In this guide, we’ll walk you through what it means, why it happens, and what you should do next.

What Does a Flashing Blue Light on a Worcester Boiler Mean?

In most Worcester Bosch boilers, especially models like the Greenstar range, a steady blue light means everything is working fine. However, a flashing blue light usually indicates there’s a fault or error that needs attention.

Is It Safe to Use Your Boiler While the Blue Light Is Flashing?

A Worcester boiler flashing a blue light usually means it has entered a fault or lockout mode, which automatically prevents it from running. This is a built-in safety feature, so while it’s unlikely to be dangerous, you should not try to force it to operate. Instead, follow the recommended steps — such as checking the condensate pipe or resetting the unit — and if the issue persists, call a qualified engineer. Using a boiler that’s repeatedly cutting out can cause further damage and leave you without heating when you need it most.

Could It Be a Fault With the Flame?

Yes, one of the most common reasons you’ll see your Worcester boiler flashing a blue light is due to a flame detection issue — often shown as error code EA on the display (if your model has one). This means the boiler is having trouble detecting the flame needed to heat your home, the possible causes include:

• A dirty or faulty flame sensor
• Low gas pressure
• Blocked flue or condensate pipe
• Ignition problems

Is Your Condensate Pipe Frozen?

During colder months, it’s quite common for the condensate pipe to freeze. When that happens, your Worcester boiler may enter a lockout mode, and you’ll see that flashing blue light again. Here is how to check:

• Look for a white plastic pipe (usually outside)
• If it feels frozen, pour warm (not boiling) water over it
• Then, try resetting your boiler

Could It Be a Gas Supply Issue?

Yes. If your gas supply is interrupted — maybe the gas valve is closed, or there’s a supply issue in your area — your boiler won’t be able to ignite properly. Again, this can be the reason your Worcester boiler flashing a blue light and stop heating, do a quick check of:

• Are other gas appliances (like your hob) working?
• If not, it might be a wider gas issue

Should You Try Resetting the Boiler?

Yes, in many cases, a simple reset can do the trick.

• Press the reset button (usually marked on the front panel)
• Wait a few minutes to see if the light stops flashing

If the blue light keeps flashing after a reset, it’s time to call in a professional. Contact us

Still Seeing That Flashing Blue Light? We Can Help!

If your Worcester boiler is flashing a blue light and you’re still unsure what to do next, don’t worry. Our team of experienced Gas Safe engineers can help diagnose and fix the issue quickly. Whether it’s a frozen pipe, ignition fault, or something else, we’ve got you covered.

Get in touch today and we’ll have your heating back in no time.

Can I Prevent This from Happening Again?

Absolutely. Regular servicing can catch small problems before they turn into big ones. Annual maintenance also keeps your boiler running efficiently and safely, get in touch with a member of our team to get your boiler serviced annually.