Worcester Bosch Boiler Fault Codes

worcester bosch boiler fault codes

Worcester Bosch Boiler Fault Codes

If your Worcester Bosch boiler has problems, it will probably shut off. This action, referred to as a 'lockout,' is taken to avoid any additional possible harm and keep you and your house safe

However, a boiler error code, sometimes known as a fault code, will often be presented on the dashboard at this instance. This dashboard code aims to keep things simple for you or the engineer to determine the issue and fix it as quickly as possible.
In this article, we have compiled common Worchester Bosch boiler fault codes and what they stand for. It will help give a better idea of what is wrong with your boiler. Read on.

Need help with your Worchester Bosch Boiler?

Croston Plumbing & Heating is here to assist. We are the number one choice for plumbing services & gas-related work. Give us a call at 01257452879.
We are Worcester Bosch accredited installers who have a wealth of expertise in installing, servicing and repairing Worcester Bosch boilers. Locally, we are known to be your go-to company for helping customer fix Worcester Bosch boiler fault codes and issues.

What are the common issues with a Worcester Bosch Boiler?

If your Worcester Bosch boiler has problems, it will probably shut off. This action, referred to as a ‘lockout,’ is taken to avoid any additional possible harm and keep you and your house safe Below are a few Worcester Bosch boiler problems that may occur over time.

Leaking boiler

The longer a Worcester boiler leak goes unattended, the more harm it may do. That's why it has to be fixed as soon as possible. Also, any electrical components that may be submerged in water should be taken extra care of to avoid costly boiler repairs due to corrosion.

Banging Noises

Ketling is the most common cause of boiler sounds in Worcester Bosch systems. This may result from a decline in water pressure, the accumulation of limescale, or a malfunctioning thermostat. Worcester boiler noise should be handled as quickly as possible, as it may lead to more severe problems in the system if left ignored.

Boiler Lockout

This is when a boiler ceases to function to prevent any further harm from being done. Boilers may lock out for various reasons, including faulty flame sensors, clogged flues or condensate pipes, a lack of fuel or insufficient fuel delivery, or excessive or inadequate boiler pressure..

Clogged Condensate Line

A condensing pipe pushes hazardous gases out of your home and into the atmosphere. The cooler months of the year bring with them the possibility of the owners encountering a clogged condensate line, but this problem can be quickly resolved using warm water.

Boiler Overheating

For example, a clogged condensate line or significant limescale buildup on the heat exchanger might cause your Worcester boiler to overheat. Also, pump or fan failure is another common reason of Worcester boiler overheating. However, it is easy for an expert engineer to identify and fix the problem.

Worcester Bosch accredited installers
As a Worcester Bosch accredited installer you can have complete peace of mind that your new boiler with be installed to the highest of standards. Additionally, we are able to provide some exclusive benefits such as extended guarantees up to 12 years and finance options should you need it.

What are the common Worcester Bosch Boiler Fault Codes?

If you’re having any of the above trouble with your Worcester Bosch boiler, the error codes below should help you track the source of the problem.

Worcester Bosch Boiler - Fan Speed Error: C6 215

This fault code indicates that the fan speed in your Worcester Greenstar boiler is too high. A suggestion is to restart your boiler as this might return the fan speed back to normal.

Worcester Bosch Boiler - Heat Control Module (HCM) Issues: 9A 362

This indicates that the control box or the Heat Control Module (HCM) is defective on your Worcester Bosch. A fault code indicating that the heat control module (HCM) is defective on your boiler, could also be a sign that the incorrect HCM fitted 9U. When you see the fault codes for the Heat Control Module (HCM) is defective an our engineer needs to be called to check your Worcester Bosch boiler as it may need replacing.

Worcester Bosch Boiler - No Flame Signal Due To Blockage or Internal Leak: EA 227

When this code appears on the control box or dashboard of your Worcester boiler, it can mean several different things. This code indicates an issue with the gas valve, as no flame can be found. This can indicate that the gas valve may need replacing, but it can also be a sign that the gas ratio control valve needs adjusting which you can do yourself. This fault code can also indicate that the condensate discharge pipe is blocked or frozen, in which airflow stopped during operation. This can cause the flue gas thermostat overheat and needs to be solved quickly.

This code can be a sign that the operation is defective. Check the connecting lead as it might show that the electrode or ignition lead has been damaged, which will prevent a flame signal. These are not issues you can handle yourself if they appear on your combi boiler. The codes fault will need to be solved by a boiler engineer or through getting a new boiler if you are no longer under warranty.

Worcester Bosch Boiler - Blocked Pump: A1 281

When this code appears, it means that the pump stuck or running with air in the system, which is an internal error. This can cause air-gas ratio control issues in the Worcester boiler.

Turning the box or heat control reset button can solve this issue in your combi boiler.

If turning the control box or heat on and off again does not solve the issue, an engineer will need to be called.

Worcester Bosch Boiler - Minimum Burner Load: EF 349

This means the primary flow is operating at minimum burner level. Once this is detected, check the safety temperature valve is between 1 and 1.5 pulses, check service mode on the burner control unit if this is the case. The temperature sensor may need replacing.

Worcester Bosch Boiler - Flow Temperature High: No Code 212

This indicates that the flow temperature too high and will need checking to return temperature back to the normal state. This can indicate that the safety temperature limiter has tripped and needs replacing. To restart the temperature flow sensor short circuit, turn the boiler off and on again to trigger the low mains voltage. This should reset the high limit thermostat activated code and prevent the gas thermostat overheat EA codes fault to appear.

Worcester Bosch Boiler - Loss Of Ionisation Detected: EA 229

This shows that there is a loss of ionisation signal detected before burner start or during operation. If the temperature sensor correctly installed, the pressure should be between 1.0 and 1.5 bars. Connections need checking, and the boiler should be reset if ionisation detected after ignition to resolve the issue.

Worcester Bosch Boiler - Flow Temperature Sensor Too High: E5 218

If the flow temperature sensor or hot water temperature sensor on the burner control unit is too high, these boiler error codes will appear. This is not something that you can change in the control box, if the temperature sensor is defective, it will need to be replaced.

Worcester Bosch Boiler - Sensor Too High: 2964 B

The signal from the heat exchanger temperature sensor is out of range for the primary flow temperature. The safety or flow temperature can be reset by turning the modulating gas valve anticlockwise to trigger a reset position.

Worcester Bosch Boiler - Low Water Pressure: 1017 W

This can be a sign that the water needs topping up in your Worcester boiler. If you are having issues with domestic hot water, then the vent system or pressure sensor may need to be replaced. If the boiler is not under warranty, it may be easier to buy a new boiler.

Worcester Bosch boiler - Safety Sensor Code 226

This means that a safety sensor has been connected to the blocking error history menu, which can be resolved by restarting the boiler. If this code does not go away, the boiler may no longer be gas safe, and you will need to buy a new boiler.

Are you interested in replacing your boiler and avoiding recurrent Worcester Bosch Boiler Fault Codes and problems?

Croston Plumbing & Heating specialist is here to assist. If there is a problem, one of our highly skilled repair technicians will be on hand to figure it out quickly and efficiently.
Whether or not you need a new boiler, our experts can help you with this decision. Get in touch with us today by calling 01257452879 or browse our site for additional information.

Here are some of the signs that you boiler needs replacing:


A sure sign that your boiler is due to be replaced is the kettling, gurgling and banging sounds that you might be hearing from your boiler when you run the hot water tap or turn on the central heating

Strange smells

While carbon monoxide does tend to be odourless, some gas companies do add a scent to help it become easier for you to detect if a leak has occurred. An eggy, sulphur-like smell around your boiler is a sure sign that there is a carbon monoxide leak and you should open all the windows and get out of the house as quickly as possible. Contact the Gas Emergency Services as soon as you can.

Yellow flame

A healthy boiler that’s working well should burn with a blue flame. However, if you’ve noticed a yellow flame on your boiler, this could be a sign of a serious issue such as a carbon monoxide problem. This gas is colourless and odourless and often, a yellow flame is the first sign that there’s a problem so it’s important to keep your eye out for it. If exposure levels are high enough, carbon monoxide can lead to serious illness or even be fatal.

Increase in energy bills

A boiler that is getting old and is increasingly less and less efficient can cost more money than most people can afford to spare. And, upgrading to a boiler that includes modern smart controls will not only improve efficiency but also give you a greater control over your energy usage and spending.

Frequent breakdown

Are you noticing that your boiler is break downing regularly or you are topping up your water pressure every week?

Reduced efficiency

When it comes to energy efficiency, some boilers are just missing the mark due to age. A boiler that’s rated ‘A’ in terms of efficiency will have an energy efficiency level of at least 90%. On the other hand, a boiler that’s rated ‘G’ will have an efficiency level of around 70%, meaning that for every £1 you spend on your energy bill, you’re losing 30p in wasted energy.

Expensive & difficult to find parts

If you’re having increasing problems with your boiler and you have been told by your boiler engineer that new parts are hard to find, it’s a clear sign that your boiler will probably need to be replaced soon. The older a boiler gets, the less likely it is that parts will be readily available. And if you’re struggling to find an engineer who is experienced with the type of boiler that you have, that’s even more reason to consider replacing it.

Do you Need Boiler Finance?

We know that if your boiler cannot be repaired and a new energy efficient boiler is required, then funds may not be available to cover the replacement. Here at Croston Plumbing & Heating, we offer a range of finance options to help cover the cost of the new boiler and installation.

What areas do we cover?

We offer our range of plumbing and heating services to customers in across the North-West. It is our aim to offer all our customers an exceptional service from start to finish. Our customers at Croston Plumbing & Heating are paramount to us and this will never change.