Worcester Boilers: Problems, Fault Codes, and their Fixes

Got no hot water, low boiler pressure, or one that’s failing to fire up altogether? No worries. This 10-minute guide to Worcester boilers problems will list typical boiler faults, explain what they mean, and recommend solutions.

We’ve also referenced detailed articles on each of the Worcester problems listed, so you can get in-depth knowledge about each individual fault.

What Happens When You Get a Worcester Boiler Fault?

With Worcester Bosch boilers, problems appear as fault codes on your control panel display.

Various boiler issues are indicated by alphanumeric error codes, all which start with “EA” and conclude with a series of numbers.

You can find the cause of each fault by referring to your boiler manual. For your convenience, however, we’ll list 10 of the most common Worcester Bosch boiler problems below.

The Top 10 Common Worcester Boilers Problems

#1 – A Blocked Condensate Pipe

Condensing boilers, like all modern ones including those made by Worcester Bosch, have a condensate pipe. This pipe vents harmful gases from your property.

Unfortunately, a blocked condensate pipe is one of the more common Worcester Bosch boiler faults — particularly in winter, if the pipe is exposed to the elements. If you experience this problem, your Worcester Bosch boiler will display an EA229 error code.

How to Fix a Worcester Bosch Boiler with Blocked Condensate Pipes

Check the condensate pipe for obstructions. If it’s ice, like we mentioned above, you can thaw the pipe out by pouring warm water over the frozen end. This should take care of the EA229 error code, and your Worcester boiler should go back to working normally.

Next, you want to stop this from happening again.

You’ll need to insulate the condensate pipe using lagging. Normal lagging will do, but ArmaFlex lagging offers much better protection.

#2 – Worcester Boiler — No Hot Water

It’s a daunting issue when you own a Worcester Bosch boiler: no hot water flowing despite things appearing as they should.

There are a few scenarios that could be behind the problem.

Possibilities include a faulty diverter valve, a lack of power, a stuck Y/S-plan valve, faulty PCB unit, or even a problem with the central heating pump.

The Fix for Worcester Boiler Problems Leading to No Hot Water

You can use our guide to diagnose a faulty diverter valve here; it’s typically the problem when the central heating system works but there’s no hot water in your taps.

If your boiler is out of warranty and needs a diverter valve replacing, it might be wise to invest that cash in a new appliance with a long boiler warranty. The cheapest place to find a replacement Worcester Bosch boiler online currently is Heatable, where these boilers are usually offered at competitive prices and with 10-year warranties.

If the diverter valve doesn’t sound like the issue, you can read more about “Worcester boiler no hot water” in our full guide on the subject.

#3 – Your Boiler Is Leaking

If your Worcester Bosch boiler is leaking, this can lead to low boiler pressure, which will in turn cause the combi boiler to lock out and thus halt your heating system.

Boiler leaks usually happen due to blown pump seals. This happens when the seals degrade over time, or experience excessive stress, such as a recent increase in flow rate on the pump.

The boiler recognises this and displays a fault code, likely A281 or EA338.

The Fix for a Leaking Boiler

Note that not all leaks are serious, so heating engineers aren’t always needed.

Before you call a Worcester Bosch boiler engineer and spend £100s, it may be worth trying to fix the leak yourself. We’ve created a guide to skip through if your boiler is leaking; it should help you diagnose the error code and get it fixed.

(Note: Once you’ve fixed the water leak, make sure you top up the boiler’s water levels so that the water pressure is around 1.3 bar)

Also note that most minor leaks can be stopped using Fernox’s F4 leak sealant for heating systems.

Remember, too, that a leak is directly connected to the boiler losing pressure…

#4 – Your Boiler Is Losing Pressure

As a rule, if your boiler problems relate to a loss of pressure, you have a leak. Sure, it might not be visible, but it’s there somewhere.

Mind you, we don’t necessarily mean a leak in the boiler itself. Any leak throughout your central heating will cause a boiler to show a dropping pressure gauge. This could be a pin-hole in a radiator, a loose connection on a rad valve, or even a weak soldering joint on the copper pipe.

The only exception to this is if your pressure sensor itself is faulty.

The Fix for Boiler Pressure Problems

When a Worcester Bosch boiler gets below a certain pressure, it will lock out. To fix this, you’ll need to re-pressurise it using the external filling loop.

But note that repressurisation a temporary fix. To solve the problem with your Worcester Bosch, and clear any error codes, you’ll need to find the leak and fix it before you top up the system.

Check out our guide to low boiler pressure here.

#5 – There Is No Power to the Boiler

Is your boiler not working due to a power loss?

Lack of power can be caused by a faulty PCB, or an RCD unit or a spur socket that’s tripped.

The PCB (Printed Circuit Board) is a key electrical component, which function as the boiler’s brain. Essentially, it allows all of the boiler’s electronics to communicate with each other. Since the PCB controls the boiler’s safety devices, it’s imperative that you get it looked at ASAP, so call your boiler care provider or a Gas Safe engineer without delay.

If your boiler’s RCD keeps tripping, it may point to some other latent issue with the boiler itself.

How to Fix a Worcester Bosch Boiler with No Power

We’ve created a guide for homeowners with no power to their boiler here, to help diagnose and fix the problem.

If the fault relates to a PCB, you may want to consider replacing your boiler altogether. You can get a price for a new Worcester boiler on-screen using this online tool from Heatable, installed by a gas safe heating engineer.

However, if your boiler RCD keeps tripping, it’s best to ask for a Gas Safe engineer to inspect your heating system for hidden faults.

#6 – Your Boiler Is Making Banging Noises (Boiler Kettling)

If your boiler problems relate to loud banging noises (aka boiler kettling), the 2 most common causes are:

• An airlock in the central heating pump
• A heat exchanger that is kettling

The Fix for a Noisy Worcester Bosch Boiler

You can learn more about noisy boilers in our guide here.

As you’ll see, an airlock in a pump on a Worcester Greenstar boiler isn’t difficult to remove.

However, if the problem with your Worcester Bosch boiler relates to a heat exchanger, you may need to replace the latter. And, unfortunately, heat exchangers are not exactly cheap. You may be better off by paying more to fit a new boiler than by replacing a heat exchanger on an old boiler that’s on its way out anyway.

#7 – Worcester Boiler Keeps Locking Out

Are you getting the Worcester 227 error code as your boiler keeps locking out? There’s likely a critical fault that’s preventing your boiler from running safely.

All Worcester Bosch boilers are fitted with safeguards. When the boiler overheats, loses pressure, or the pressure soars despite the pressure relief valve, these safeguards cause it to lock out. This safety mechanism stops the internal components of your gas boiler from getting fried, and also prevents your boiler from working if it’s dangerous to do so.

How to Fix Boiler Lockout

If your Worcester 227 fault is manifesting as a constant or intermittent lockout, we’ve created a guide just for you. Jump over to our ultimate guide to boiler lockouts here.

#8 – Worcester Boiler Overheating

Have you checked on your Worcester boiler problems, and found an error code like D1 286, E5 218, E5 332, E9 219 or E9 224?

These error codes indicate overheating.

If you’ve got a Worcester Bosch boiler that’s overheating, the problem could be caused by things like a faulty fan, pump, blocked PRV, or even condensate blockage. Either way, there’s something that doesn’t let your boiler function properly, and the situation is potentially hazardous.

The Fix for an Overheating Boiler

If your EA fault code indicates an overheat, you can learn more from our quick guide on boilers overheating here. However, do keep in mind that with the exception of clearing out a blocked condensate pipe, these fixes will require a Gas Safe engineer’s expertise to right the problem with your heating system.

#9 – Worcester Boiler Pilot Light Keeps Going Off

For older Worcester Bosch boilers, problems with ignition may stem from an issue with the pilot light. That’s because these older models aren’t equipped with electronic ignition, and thus rely on the pilot light to fire up.

If you find that this light isn’t working properly — and neither is the boiler — it could be due to these root causes:

• Malfunctioning thermocouple — This critical safety device automatically shuts off the gas supply if the pilot light isn’t lit. If this safeguard breaks, it may cut off the gas even though there isn’t a thing wrong with the light itself.
• Gas supply issue — If your other gas appliances aren’t working, it’s a good sign that your trusty Worcester boiler is not at fault; your gas supplier is.
• Carbon deposits on the light — Over time, carbon build-up may obstruct the light and cause it to malfunction.

How to Fix Combi Boilers Not Firing Up

If a gas supply issue is causing your pilot light to go off (along with all of your other gas appliances), then the obvious step would be to ring up your gas supplier.

However, if your other gas appliances are functioning well, you should call a Gas Safe engineer to inspect your boiler and determine the underlying issue. They can replace a broken thermocouple and/or remove carbon deposits from the pilot light. In either scenario, this isn’t a DIY-type job.

If your boiler won’t ignite but the pilot light works just fine, read our thorough guide to common ignition problems and learn about other potential causes.

#10 – Worcester Boiler Not Responding to Thermostat Commands

You most likely control your boiler via a thermostat, or a smartphone companion app. If your boiler rebels and stops obeying your commands, you’re looking at several possible causes:

• Your boiler is off
• Thermostat batteries are flat
• The thermostat is unable to communicate with the boiler

The Fix for Thermostat Issues

If you’re boiler is off, simply switch it back on and go on about your day; monitor the appliance to make sure there’s no underlying cause that locks it out.

Check your thermostat’s batteries — if they’re flat, replace them; simple as that.

Here’s where it gets tricky. Wireless thermostats can have trouble communicating with the boiler’s relay if there’s a physical obstruction to the signal. Likewise, hard-wired thermostats can suffer from faults in the wiring. In either scenario, we’ll urge you to get a Gas Safe engineer to help you pinpoint and fix the problem.

FAQs About Worcester Bosch Boiler Faults

Before we finish, let’s go over a few FAQs that often surround Worcester Bosch boiler faults.

Why is my Worcester boiler not firing up?

There are plenty of reasons a Worcester boiler (or any boiler, really) may not fire up, but most have to do either with gas supply, ignition, or an inability to operate safely.

For example, if there’s insufficient gas supply, the ignition electrodes are faulty, or the burner is clogged, the boiler will fail to fire up.

Likewise, if the boiler can’t operate safely due to an issue like a frozen condensate pipe, clogged flue, or faulty fan, it will remain locked out until the root issue is resolved.

In most cases, fixing the underlying problems will require the assistance of a Gas Safe registered engineer.

How do I reset my Worcester boiler?

With most Worcester Bosch boiler models, resetting the boiler is as easy as pressing and holding the reset button for about 3-5 seconds. The button is typically located on the boiler control panel.

Note that simply resetting the boiler will not eliminate the fault that caused it to lock out in the first place. You should only reset your boiler once all faults and errors have been resolved.

Why is my Worcester boiler banging?

If your Worcester Bosch boiler is banging, there’s a good chance that an airlock has appeared in the pump.

Alternatively, it could be because the heat exchanger suffers from limescale build-up, and your boiler is ketting.

Common Worcester Boiler Issues — What’s Next?

For most Worcester boilers, problems should be few and far in between. Something breaking isn’t necessarily a representative example of the brand’s overall quality — but it can still happen. If yours malfunctions, however, we hope that this guide has supplied enough information to get you started. 

Are you still having problems with your Worcester Greenstar boiler and need a boiler repair or new boiler quote?

Get a fixed online replacement price from Heatable here.

And, if you have a question you’d like to ask, please leave us a comment below.