Skip to main content
F28 FAULT CODE
Heatline

Ignition Failure

Medium Severity DIY Check Possible

The most common Heatline fault code. The boiler has failed to ignite. Very commonly caused by a frozen condensate pipe in winter. F28 on Heatline boilers is equivalent to F28 on Vaillant boilers — they share the same code system.

Cold Weather Note

F28 in winter on Heatline boilers is almost always a frozen condensate pipe. Thaw before resetting.

Step-by-Step Fix Guide

  1. Step 1

    Check gas supply — try other gas appliances

  2. Step 2

    In cold weather, check the condensate pipe for ice and thaw with warm water

  3. Step 3

    Press the reset button (usually a flame icon)

  4. Step 4

    If fault persists, call a Gas Safe engineer to check gas valve and ignition electrode

Gas Safe Reminder

Work on gas appliances must be carried out by a Gas Safe registered engineer. The steps above cover safe checks a homeowner can perform - any internal component replacement requires a qualified professional. If in doubt, always call an engineer.

Are you a Gas Safe Engineer?

Access technical fault data, wiring diagrams, and parts lists. Free for verified Gas Safe engineers.