Eazy Guides

The Vaillant boiler F25 fault code means the flue gas temperature has risen too high and the boiler has switched itself off as a safety measure. In everyday terms, the…

The F28 fault code appears when your Vaillant boiler tries to light but cannot detect a flame after several attempts. It then locks out as a safety step so unburnt…

The F23 fault code is a safety message that appears when your Vaillant boiler detects an unusually large temperature difference between the hot water leaving the unit (the flow) and…

The F2 fault code appears when your Ideal boiler detects that the flame has gone out or failed to stay lit during operation. This safety lockout stops the unit to…

The Glow-Worm boiler F9 fault code appears when your heating system pressure drops too low for safe operation. This common issue stops the boiler to protect the pump and heat…

The E9 fault code appears when your Worcester boiler detects that the temperature has risen too high triggering the safety thermostat. This lockout stops the unit to protect internal components…

The best storage combi boilers in 2026 are the Viessmann Vitodens 111-W, the Viessmann Vitodens 222-F, the Vaillant ecoTEC plus Combi Store, the Glow-worm Energy Store 35, and the Worcester…

The best boilers for landlord rental properties in 2026 are the Ideal Logic Max, the Worcester Bosch Greenstar 4000, the Viessmann Vitodens 050-W, the Alpha E-Tec, and the Baxi 600. …