Code 228 on a Worcester Bosch is the odd one out in the flame family: instead of failing to find a flame, the boiler believes it can see one when nothing is burning. On Compact models you’ll often see it written as “F7 228”. We’re Clever Energy Boilers, a Gas Safe registered team and accredited Worcester Bosch installers in Bingley, working across Yorkshire and the Humber, the North West and the Midlands. When an older Worcester starts throwing codes like this, a replacement Worcester Bosch boiler is the better option longer term, giving you better efficiency and an end to repair bills.
We’ve fitted more than 25,000 boilers over the last 15 years, so we know how often a nagging sensor fault is the first sign of an ageing unit. Here’s what 228 means in plain English, what might be behind it, and how far a homeowner can sensibly go.
What does the Worcester Bosch 228 fault code mean?
Every time the boiler fires, a sensing probe checks that a flame is present. With 228 the probe reports a flame signal at a moment when there shouldn’t be one, for example just before the burner starts. On the Greenstar 8000 Style it appears as 228 alone, described as a flame signal without a flame. On Si and CDi Compact boilers it’s F7 228, flame detected before the burner started.
A quick way to remember the difference: our 227 fault is the boiler seeing no flame when it expects one, and 228 is the boiler seeing a flame it doesn’t expect.
What triggers a false flame error on a Worcester boiler?
The usual suspects, roughly from simplest to most involved:
- Moisture on the electrode assembly, often from a leak or a condensate problem nearby
- A damaged or worn ionisation cable
- A faulty air and gas ratio control valve letting gas through when it shouldn’t
- A blocked flue or a fault on the circuit board
Sources disagree a little on which of these is most common, and it varies by model, so treat the list as possibilities rather than a diagnosis.
Should I be worried about a Worcester 228 fault?
Take it seriously, but there’s no need to panic. The boiler locks out and stops firing, which is the safe response. Because a faulty valve is one possible cause, though, it’s worth being careful. If you smell gas, switch nothing on, open the windows, turn the gas off at the meter and ring 0800 111 999 straight away.
What can I do myself about a Worcester 228 error code?
Less than with most codes, and that’s deliberate. The likely causes sit inside the sealed combustion area, which is for Gas Safe registered engineers only. There are still a few sensible things to look at:
- Check the pressure gauge. Aim for roughly 1 to 1.5 bar when the system is cold. To top up, switch the boiler off, connect the filling loop, open the valves slowly until the needle reaches the right level, then close them tightly.
- Look underneath and around the boiler for drips or damp patches, and check that the outside condensate pipe isn’t frozen. If it is, pour warm water over it.
- Reset the boiler once.
If 228 is back after that, stop. Don’t remove the casing and don’t keep resetting.
Why does the 228 fault code come and go on a Worcester?
An intermittent false signal usually points to damp or wear. Damp electrodes dry out and behave for a while, then the code returns on the next cold start. A worn valve or cable can pass a test one day and fail the next. The pattern of “fine for a week, then locked out” is typical of parts reaching the end of their working life.
When does a new Worcester Bosch make better sense than fixing a 228 error?
If the code is on a boiler under five years old, a single visit may sort it. On an older Worcester it’s a different calculation. Consider replacement if:
- The boiler is over 8 years old and losing efficiency
- This is the second or third fault code this year
- The fault involves the gas valve, which is among the costlier parts
- You’re worried about relying on the boiler through winter
Our guide to when your boiler needs replacing lays out the signs in more detail.
Replacing your Worcester Bosch with Clever Energy
We fit Worcester Bosch boilers from Bingley to Bradford, Leeds, Huddersfield and Harrogate, throughout Yorkshire and the Humber, across the North West in places like Preston, Bolton and Warrington, and in the Midlands including Derby, Nottingham and Coventry. Read about our Worcester Bosch boiler installation or build your quote online to see a fixed price without anyone visiting your home first. Questions about a new boiler? Call 0330 055 2210 any weekday between 8am and 8pm.
Worcester Bosch 228 fault code FAQs
What is the difference between F7 228 and 228 on a Worcester error code?
Nothing about the fault itself. Compact models show the F7 prefix before the number, while the Greenstar 8000 Style shows 228 alone. Both mean the boiler detected a flame that wasn’t there.
Can I clear a Worcester 228 fault by resetting the boiler?
You can reset once. If it clears, the cause may have been damp that dried out. If it returns, a part is likely failing and an engineer needs to look.
Is the Worcester 228 error a sign of a gas leak?
Not by itself, but a faulty gas valve is one possible cause, so never ignore a smell of gas. Call 0800 111 999 if you notice one.
Could damp cause the F7 228 fault code on a Worcester?
Yes. Moisture on the electrode assembly is one of the commonest reasons, which is why a leaking or frozen condensate system gets checked early.
Is it worth repairing an older Worcester Bosch with this error code?
Once a boiler passes 8 years, we’d usually look at replacement. A new Worcester Bosch is more efficient and removes the repeat call-outs.
More Worcester Bosch error codes
The false-flame fault belongs alongside a couple of other gas-valve codes. Before this one, have a look at the Worcester Bosch 227 fault code; after it, the Worcester Bosch FA fault code covers the next code in the set. The full list sits on our Worcester boiler error codes guide.
