Boiler Guides

The FL fault code is signalling that your Ideal boiler has either failed to ignite or has lost the flame during operation, and it’s locked out as a result. Ignition…

The F3 fault code means your Ideal boiler has detected a problem with the flow and return temperature readings, usually because the difference between them has become too great or…

The F1 fault code means your Ideal boiler has detected that your system’s water pressure has dropped too low for it to operate safely. Boilers rely on a set amount…

The L2 fault code means your Ideal boiler has detected a problem with the fan and has locked itself out as a safety precaution. The fan plays a key role…

British Gas is one of the most recognisable names in UK home heating — and for many homeowners, it’s the first port of call when a boiler needs replacing. As…

Average Boiler Prices & Installation Costs in the UK for 2026A new boiler in the UK realistically costs between £1,800 and £5,500 fully installed for most gas-fired systems — and that’s once…

Vaillant boiler error codes are the diagnostic messages your boiler displays whenever it detects a fault, whether that’s low water pressure, an ignition failure, a sensor issue, or a genuine…

Vaillant’s own manual describes the F27 fault code as a safety switch-off caused by flame simulation, meaning the electronics have picked up what looks like a flame, or a flame-like…

If your Vaillant boiler has locked out showing F25, it’s warning you that the temperature of the gases leaving through the flue has climbed higher than it safely should, or…

The Vaillant boiler F28 fault code means the flame signal was not detected during the ignition phase, so the control board shuts the gas valve and locks the boiler out…

The Vaillant boiler F23 fault code is a safety switch-off triggered when the difference between the flow and return pipe temperatures exceeds roughly 35 degrees Celsius, which tells the boiler…