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Worcester Bosch Boiler EA 234 Fault Code


The Worcester fault code EA 234 gas valve Q & A or require an engineer for an emergency boiler repair.


The Worcester Boiler Fault Code EA 234 Error Common Q & A


Just below, we have a list of common questions relating to the EA 234 fault code on the Worcester Bosch Boiler.

Worcester Boiler EA 234 Fault Code Error
  • What does the EA 234 fault code mean on my Worcester Bosch boiler?
  • What does the gas valve do on my boiler?
  • What is causing the EA 234 fault code to occur on my boiler?
  • Is a boiler with an EA 234 fault code dangerous?
  • If the EA 234 fault code is being displayed, will I need a new boiler?
  • Can an incorrectly adjusted gas valve be adjusted to work with my boiler?
  • How much does a new gas valve cost to replace in a Worcester boiler?
  • What other faults can occur with a gas valve that cause an EA 234 fault code?
  • How will a boiler engineer determine if it’s the PCB that’s at fault?
  • If my PCB has water damage, should I repair it?
  • What are common signs that the boiler’s PCB is faulty?
  • The PCB and gas valve aren’t faulty, what else could cause the EA 234 fault code to be displayed?

What does the EA 234 fault code mean on my Worcester Bosch boiler?


If your boiler is showing an EA 234 fault code, there’s an issue with the gas valve.

The most specific indication from Worcester is that the coil is disconnected. However, there are a range of other faults that can occur with these valves.


What does the gas valve do on my boiler?


The gas pipework is supplied with gas via the meter. This travels to the boiler and the flow is controlled by the gas valve.

For instance, when you turn up your thermostat or turn on a shower, the gas valve will open. When you turn off a thermostat or shower, the gas valve will close.

For the valve to know when it needs to open and close, it needs to communicate with the PCB (printed circuit board).

The PCB is the heart of any boiler, sending and receiving signals from all important boiler components.

What is causing the EA 234 fault code to occur on my boiler?


The most obvious fault would be an incorrectly adjusted or faulty gas valve.

However, the PCB can’t be ruled out as a culprit. As this component controls the valve, there’s a chance it could be sending and receiving incorrect signals, not allowing the gas valve to work correctly.

Is a boiler with an EA 234 fault code dangerous?


Although any boiler fault can potentially cause danger, the boiler lock out mechanism is designed to protect you from that danger.

What the lock out suggests is that if the boiler was to operate it could be dangerous, or it could start to damage internal components.

Whilst it might not be dangerous in its locked-out state, that doesn’t mean you should try resetting the boiler to clear the fault.

Boilers should be worked on by Gas Safe qualified engineers. Once they’re confident they’ve fixed the fault, they’ll reset your boiler for you.

More importantly, if another fault occurs whilst they’re testing the boiler, they’re on hand to fix it.

If the EA 234 fault code is being displayed, will I need a new boiler?


If it’s the gas valve that’s the only issue, it’s unlikely you’ll need a new boiler.

If the valve does need replacing, the gas engineer will have to inspect other expensive components in the boiler. Replacing just the valve is a cost-efficient repair.

However, if parts such as the heat exchanger and PCB are also looking like they need replacing, this rolls into the territory of a replacement boiler being more cost effective.

Can an incorrectly adjusted gas valve be adjusted to work with my boiler?


Gas valves can be adjusted. If you’ve had a new gas valve fitted, it’s likely the previous engineer didn’t adjust and test the valve correctly.

On a similar note, if this is a new boiler, there’s a small chance that it’s a manufacturing fault with the valve.

Before a Gas Safe engineer adjusts the valve, they’ll need to check its operation. There’s little point adjusting a valve, if it’s sticking.

Sticking gas valves are common, and can sometimes be freed. And, that’s going to mean avoiding a costly bill for a replacement.

How much does a new gas valve cost to replace in a Worcester boiler?


For a diagnostic and replacement (parts included), you should expect to pay around £300 for a new valve. This will vary slightly depending on the model of boiler, and therefore, the cost of the valve itself.

Generally, the entire process will take a boiler engineer less than a day.

What other faults can occur with a gas valve that cause an EA 234 fault code?


Besides the valves getting stuck open as we’ve previously mentioned, it’s common to have faulty wiring or connections to and from the PCB/gas valve.

These connections can be re-secured or replaced, as can the wiring.

Typically, you’ll want your gas engineer to find out what’s caused these issues. If it’s old age, a simple reconditioning of the valve’s electrics is all that’s needed.

However, electronic components in boilers are prone to water damage. If this is what’s caused the gas valve fault, it needs to be fixed to stop it happening again, and causing damage to other parts.

Finally, you could have a gas valve that’s letting-by. That means gas is leaking into the boiler when the valve should be closed. This is either due to it being stuck, or open slightly.

How will a boiler engineer determine if it’s the PCB that’s at fault?


Like the gas valve, the boiler’s PCB can be tested with a multi-meter. And similarly, any loose or damaged connections can be repaired or replaced.

The main thing a boiler engineer will be looking out for is that there’s no water damage.

Water damage can cause massive amounts of internal boiler damage, as many of the parts inside are electrical; including the PCB.

Typical signs of water damage would be burnt out connections and sections of wiring.

If my PCB has water damage, should I repair it?


The PCB is possibly the most expensive part in your Worcester boiler, costing over £500 to replace in some specific models.

That said, it rarely makes sense to repair an old and tired PCB.

Usually, it makes sense to either replace the whole PCB, or to consider getting a quote for a new boiler.

The more important thing to consider here, is exactly what is leaking. It’s not just the PCB that is exposed if there’s a boiler leak; anything electrical could be damaged.

So, the leak that’s caused the fault here needs to be fixed before moving on to other repairs, such as the PCB or gas valve.

What are common signs that the boiler’s PCB is faulty?


If you suspect the boiler’s PCB is causing the EA 234 fault code to be displayed, you may have noticed your boiler acting strangely.

As the PCB controls all electronic components, it may be sending or receiving the wrong signals causing issues like:

  • Radiators too hot/too cold
  • Hot water works, but heating doesn’t (and vice-versa)
  • The boiler cycles on and off randomly
  • It doesn’t respond to the settings on the timer

These are all things that could have been caused by bad signals, and a faulty PCB.

The PCB and gas valve aren’t faulty, what else could cause the EA 234 fault code to be displayed?


The fault code system on boilers isn’t perfect, but it usually gives a good indication of where to start the diagnostic process.

If the PCB and gas valve aren’t showing faults, the next place to look is the gas supply.

Other Worcester boiler issues


More more boiler issue regarding the Worcester Bosch the please visit the Worcester Boiler Problems And Cures page.