The 6 Most Common Worcester Bosch Boiler Problems & How To Repair Them

The 6 Most Common Worcester Bosch Boiler Problems & How To Repair Them

Posted on September 5, 2021

We install Worcester Bosch boilers and have an expert team of boiler engineers covering the South Coast that are skilled in the installation and repair of Worcester Bosch boilers.

As with all appliances, there will be occasions where sometimes they will need to be repaired or you come across an issue or fault.

For anyone who has a Worcester Bosch boiler, here is a handy guide to help you understand error codes and identify when you need to call a Gas Safe registered heating engineer to come and take a look.

What are the most common Worcester Bosch boiler problems?

Let’s go through some of the most common error codes you might encounter with a Worcester Bosch boiler, how you can go about getting the issue resolved and whether you need to call a heating engineer.

Less than 1bar on the pressure gauge –

Not quite an error code, but if your pressure gauge is reading less than 1bar then it’s indicating low boiler pressure.

What can cause low boiler pressure?

Bear in mind that it’s quite normal for a boiler to slowly lose pressure over time, but a very sudden drop in pressure could indicate a leak somewhere in your system. It can also be caused if you’ve recently bled your radiators.

How do I fix low boiler pressure?

It’s a common one, but also something relatively easy to sort out. You can read more about fixing low boiler pressure here

Do I need a heating engineer to fix this?

If it is due to a leak, then yes.

A7 –

This error code indicates that there is no hot water.

What could cause no hot water?

There are quite a few different things that can cause your heating system to stop heating your water. Things like thermostat issues, low water levels, broken diaphragms, motorised valves failing or airlocks.

How do I get my hot water to come back on?

If your Worcester Bosch boiler has stopped making hot water, this isn’t something you can try to resolve yourself. Call a Gas Safe registered engineer and leave it to the experts to sort out for you.

Do I need a heating engineer to fix this?


– A281 / EA338 –

This error code suggests that there is a leak somewhere in your system. It’s very important to get any suspected leaks fixed as soon as possible to prevent further damage to the boiler, other components and especially electrical parts as well as other areas of your home.

What can cause a leak in your heating system?

The most common culprits of leaky heating systems or boilers are internal components becoming broken. You can read more about what to do if your boiler has a leak here

Can I fix a leak in my boiler myself?

The first thing you can do if you think you’ve got a leak or your Worcester Bosch is displaying the above error code is to turn off your water supply to prevent damage. The actual leak won’t be something you can resolve yourself so you will need to call a boiler engineer to come and find the leak and get it fixed.

Do not attempt to fix a leaking Worcester Bosch boiler by yourself.

Do I need a heating engineer to fix this?


– A41 –

This error code displays when there are banging noises in your boiler or heating system.

Why would my boiler be making banging noises?

The most likely reason for a boiler that’s banging is kettling. This is usually one of three things: a build-up of limescale, poor water pressure or a faulty thermostat. You can read more about boilers making banging noises here

How do I stop my boiler from making a banging noise?

When banging in your heating system is due to dirt and debris, you will need to get a heating engineer to come and take a look. They will likely perform a powerflush which will help to remove the limescale and sludge that are causing problems inside the system. This will mean that the water will once again be able to flow freely around the system and bring those banging noises to a stop.

If you’re keen to stop sludge building up in your heating system before it can cause problems, you might want to consider having a magnetic filter installed. This nifty little component can be fitted inside the pipe and attracts rust, sludge and debris before it can build up and cause issues.

Do I need a heating engineer to fix this?


– FD231

This error code, and/or a slow or fast flashing light indicates that your Worcester Bosch boiler is locking out.

Why does my boiler keep locking out?

As with many appliances, if it becomes unsafe to operate then it will automatically lock out so as not to cause any danger. Therefore, if there is a potentially dangerous fault in your Worcester Bosch boiler, it will lockout until the issues is fixed.

Possible causes include a faulty flame detector, blocked condensate or flue pipes, a problem with fuel supply, and high or low boiler pressure.

You can read more about a boiler locking out here.

How can I fix my boiler if it’s locking out?

The only way to fix a boiler that is locking out is to resolve the issue that’s causing the lockout. This means calling a registered heating engineer to come and identify the fault and then carry out the necessary repair. There is also usually a Worcester Bosch error code being displayed to help you figure out what the issue is.

Do I need a heating engineer to fix this?


– EA229 / D5 –

If you are seeing the above error code then your looking at a blocked condensate pipe.

What is a condensate pipe?

If you have a condensing boiler, then it will have a condensate pipe. During operation, your boiler will produce harmful gases – This pipe allows these harmful gases to safely be removed from the boiler and your property.

Obviously, if a blockage occurs in this pipe then harmful gases wouldn’t be safely removed and therefore this is why the boiler will lockout.

How can I fix a blocked condensate pipe?

The most common cause of a blocked condensate pipe is ice – In very cold weather they are prone to freezing as their location is outside.

Thankfully, this issue is something you can usually sort out yourself. Using warm water (not boiling water) pour it over the area of the condensate pipe that’s blocked and frozen to thaw it out.

If you don’t feel confident doing this yourself or are in any doubt about what the blockage is, then don’t hesitate to call a Gas Safe registered engineer and leave it to the experts.

Do I need a heating engineer to fix this?

If it’s frozen and you feel confident doing it yourself then no.

Boiler Warranty from Worcester Bosch

Most boilers from Worcester Bosch come with a standard 2 year warranty, with some models offering an extended 5 year warranty. Always refer to your warranty for clarification.

If you want to ensure that your warranty stays valid for its duration, then you will need to make sure you keep up with annual boiler services. Give us a call today if you’ve suddenly remembered you need to arrange yours!


Need a New Boiler?

If you think you might need a new boiler then get in touch with us today for a free boiler quote, especially if your current Worcester Bosch boiler has been heating your home for a long time.

Whilst a new boiler is undoubtedly an expense, it could actually save you money in the long run. An old, inefficient boiler could be increasing your energy bills month to month, whereas research suggests that a new boiler could help you save up to £305 a year from your heating bills.

We have trusted, expert heating engineers across the South of England covering Wiltshire, Berkshire, Surrey, South London, Hampshire, Sussex and Dorset. Get in touch with us today or head to our website for a free boiler quote.


Has Your Boiler Warranty Expired?

If your current boiler warranty has ended but you feel like you would still like a level of cover, then head to our website for more information on our Boiler Care Plans from us here at Aura Heating. Our tailor-made cover starts from just £8.50 per month and include:
– All parts and labour
– No excess to pay when you need us
– 24/7 emergency call out

We’ve operated in the South of England for 15 years and all our engineers are employed rather than sub-contractors. Let our care plans provide you with complete peace of mind that when your boiler or heating system fails, we’ll be there to get it up and running again.