If your Worcester Greenstar CDI or CDI Classic boiler is displaying an EA fault code, one of the most common causes is an intermittent ignition failure. While the EA fault can be triggered by several components, one often-overlooked issue is a sticking fan bearing plate.

At Certificates4UK Ltd, we’ve diagnosed this fault on numerous Worcester boilers across West Molesey, Thames Ditton, Esher, Walton-on-Thames, Kingston upon Thames, Richmond, and the surrounding Surrey area. Understanding this common issue can help Gas Safe engineers identify the fault quickly and avoid unnecessary replacement of other components.

In this guide, we explain why the fault occurs, how to inspect the fan bearing plate, and the best long-term repair.

---

What Does an EA Fault Mean?

An EA fault on a Worcester Greenstar CDI boiler indicates that the appliance has failed to establish or maintain a stable flame during ignition.

The boiler attempts to ignite, but the flame is either not detected or is extinguished shortly afterwards, causing the appliance to lock out as a safety precaution.

Although ignition electrodes, gas supply problems, or blocked condensate systems can all contribute to an EA fault, the fan assembly should never be overlooked.

---

A Common Cause – Sticking Fan Bearing Plate

One of the most common causes of intermittent EA faults is a sticking fan bearing plate.

The bearing plate contains flexible rubber flaps that allow the fan to operate correctly during ignition.

Over time, heat, age, and combustion deposits can cause these rubber flaps to stick against the fan housing.

When this happens:

• Airflow becomes restricted.
• The fan may not reach the required operating speed.
• Combustion becomes unstable.
• The boiler locks out with an EA fault.

This problem is often intermittent, making diagnosis more difficult.

---

Common Symptoms

You may notice:

• Boiler occasionally displaying an EA fault.
• Boiler resetting successfully before failing again.
• Ignition attempts followed by lockout.
• Intermittent heating and hot water.
• Fault occurring more frequently over time.

Because the fan may operate normally during some ignition cycles, this fault can easily be mistaken for other ignition problems.

---

Step-by-Step Diagnosis

Step 1 – Isolate the Boiler

Before carrying out any work, isolate the electrical supply and follow the manufacturer’s safety procedures.

---

Step 2 – Remove the Fan Assembly

Carefully remove:

• Fan assembly
• Gas supply tube

This provides access to the fan bearing plate.

---

Step 3 – Inspect the Bearing Plate

Check whether the rubber flaps move freely.

If they stick to the casing or fail to move smoothly, the bearing plate has deteriorated.

Even slight resistance can affect combustion airflow.

---

Step 4 – Replace Rather Than Clean

Although cleaning may provide a temporary improvement, experience has shown that replacement offers a much more reliable long-term repair.

Installing a new bearing plate significantly reduces the likelihood of repeat EA faults.

---

Step 5 – Fan Speed Adjustment (Where Applicable)

Some engineers choose to increase the fan speed parameter to approximately 55 Hz where permitted by the manufacturer’s specifications.

This can help prevent repeat sticking issues on certain boilers.

Always follow the latest Worcester Bosch service instructions and combustion requirements before making any adjustments.

---

Quick Fault Summary

Symptom	Possible Cause	Recommended Action
EA fault	Sticking fan bearing plate	Replace bearing plate
Intermittent ignition	Restricted airflow	Inspect fan assembly
Boiler resets temporarily	Fan not operating consistently	Replace worn components
Repeated lockouts	Bearing plate deterioration	Full inspection required

---

Engineer’s Tip

When diagnosing an EA fault, don’t immediately replace the ignition electrode or gas valve.

Always inspect the fan assembly first.

A sticking bearing plate is a common fault that can easily be overlooked and may save significant diagnostic time.

---

Why This Fault Is Often Misdiagnosed

Because the boiler may operate normally for several days before the fault returns, engineers sometimes replace:

• Ignition electrodes
• Flame sensing electrodes
• Spark generators
• PCBs

without identifying the real cause.

Following a logical diagnostic process prevents unnecessary replacement of expensive components.

---

Preventative Maintenance

Annual boiler servicing helps identify worn fan components before they begin causing intermittent faults.

During servicing, engineers should inspect:

• Fan condition
• Bearing plate movement
• Burner condition
• Combustion seals
• Ignition electrodes
• Flame detection
• Condensate trap
• Gas pressures

Preventative maintenance improves reliability and reduces unexpected breakdowns.

---

Why Choose Certificates4UK Ltd?

Since 2011, Certificates4UK Ltd has been repairing Worcester Bosch boilers throughout Surrey.

Our Gas Safe engineers regularly diagnose and repair EA faults in West Molesey, Esher, Thames Ditton, Walton-on-Thames, Weybridge, Kingston upon Thames, Richmond, and surrounding areas.

We use a systematic diagnostic approach to identify the true cause of boiler faults before recommending replacement parts, helping homeowners avoid unnecessary repair costs.

---

Frequently Asked Questions

Can I reset an EA fault?

A reset may temporarily restore operation, but if the underlying fault remains, the EA code will usually return.

Is an EA fault always caused by the fan?

No. EA faults can also result from ignition electrodes, gas supply issues, flame detection problems, or combustion faults. A full diagnosis is essential.

Should the fan bearing plate be cleaned?

Replacement is generally recommended, as cleaning often provides only a temporary solution.

Can homeowners repair this fault?

No. Work on combustion components must only be carried out by a Gas Safe registered engineer.