If your Glow-Worm or Vaillant boiler displays the Fix Boiler F28 Error code, the boiler is struggling to ignite. This can leave you without heating or hot water, causing inconvenience—especially in winter.
This guide will explain what the F28 fault code means at the Free Boiler Scheme, why it happens, and how to fix it. Whether you’re a homeowner or landlord, this step-by-step guide will help you troubleshoot the issue.
What is the F28 Error Code on Glow-Worm & Vaillant Boilers?
The F28 fault code indicates that your boiler has failed to ignite after several attempts. The boiler won’t fire up without a successful ignition, leaving you with no heating or hot water.
Vaillant and Glow-Worm boilers have built-in safety mechanisms. If ignition repeatedly fails, the boiler locks out to prevent further damage.
What Causes the F28 Fault?
Several factors can trigger the Fix Boiler F28 Error. Here are the most common ones:
1. Gas Supply Issues
- No gas supply or low pressure can prevent ignition.
- Check if your gas meter is on and working correctly.
- If you have a smart meter, ensure it hasn’t locked out the gas supply after an outage.
2. Frozen Condensate Pipe
- The condensate pipe (leading outside) can freeze in winter, blocking the gas flow.
- If frozen, the boiler won’t ignite and may show an F28 fault.
3. Ignition Electrode Failure
- The ignition electrode creates the spark that ignites the gas.
- A faulty, dirty, or misaligned electrode may cause ignition failure.
4. Faulty Gas Valve
- The gas valve regulates gas flow to the burner.
- If stuck or broken, gas won’t reach the boiler, causing an ignition failure.
5. Blocked or Faulty Flame Sensor
- The flame sensor detects whether a flame is present.
- If it’s dirty or faulty, the boiler may not recognize the flame and shut down.
How to Fix the F28 Error on Your Boiler?
1️⃣ Check Your Gas Supply
🔹 Ensure your gas meter is switched on and gas is available.
🔹 Try turning on a gas appliance (e.g., your stove) to confirm gas is flowing.
If there’s no gas, contact your energy supplier for assistance.
2️⃣ Reset Your Boiler
🔹 Turn off the boiler and wait for 5 minutes.
🔹 Press the reset button (refer to your user manual).
If the F28 error persists, proceed to the next step.
3️⃣ Defrost the Frozen Condensate Pipe
🔹 If the weather is freezing, your condensate pipe (outside wall pipe) may be blocked.
🔹 Pour warm (not boiling) water over the pipe to melt any ice.
Reset the boiler and check if the error disappears.
4️⃣ Inspect the Ignition Electrodes
🔹 If you have experience, check if the electrodes are dirty or misaligned.
🔹 If unsure, contact a Gas Safe registered engineer for inspection.
5️⃣ Check the Gas Valve
🔹 If the gas valve is stuck, it may need cleaning or replacing.
🔹 This requires an expert, so call a professional engineer.
When to Call a Gas Engineer?
If you’ve tried these fixes and the F28 error still appears, it’s time to call a gas-safe engineer. They can:
- Clean or replace faulty ignition components.
- Fix gas supply or pressure issues.
- Repair or replace the gas valve.
❌ Never attempt to open your boiler or tamper with gas components yourself.
Preventing the F28 Error in the Future
Schedule Annual Boiler Servicing – A yearly check prevents ignition issues.
Protect Your Condensate Pipe – Insulate it to prevent freezing in winter.
Ensure Proper Gas Supply – If you notice low pressure, check it.
Check Ignition Electrodes & Flame Sensors – Regular maintenance helps avoid faults.
Why Choose the Free Boiler Scheme?
If your boiler frequently shows the F28 fault, it may be time for an upgrade. You may qualify for a brand-new, energy-efficient boiler through the Free Boiler Scheme at no cost.
Who Qualifies for a Free Boiler?
Homeowners & Tenants on Benefits – You may be eligible if you receive Universal Credit, Pension Credit, or other government benefits.
Low-Income Households – If your household income is below a certain threshold.
Energy-Inefficient Boilers – You may qualify for a free replacement if your boiler is over 15 years old.
How to Apply for a Free Boiler?
✔️ Step 1: Check your eligibility online.
✔️ Step 2: Submit a simple application.
Step 3: Our professional installer will assess your home.
Step 4: If approved, your new boiler is installed for free!
Don’t wait! Check if you qualify for a free boiler today!
Final Thoughts
The F28 error code is a common issue in Glow-Worm & Vaillant boilers. Troubleshooting steps like checking your gas supply, resetting the boiler, and thawing a frozen condensate pipe can fix it. However, if the problem persists, always consult a gas-safe engineer.
If your boiler is old or unreliable, upgrading to a new boiler through the Free Boiler Scheme can save you money and improve energy efficiency.
Apply today and enjoy a warm, worry-free home!
