36 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
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Your boiler is failing to light the internal burner, so it has safely shut itself down to prevent a gas build-up.
Your boiler has temporarily shut down because it has detected that it is getting too hot inside.
Your boiler has temporarily stopped working because it detected that the main heat exchanger was getting too hot, which is a built-in safety feature to prevent damage.
Your boiler has lost its electrical communication with the gas valve, meaning it cannot safely release gas to heat your home.
Your boiler has safely shut down because it detected a blockage or issue with the pipe that carries exhaust gases outside your home.
Your boiler has detected an issue with the water pressure sensor, meaning it cannot accurately read the pressure inside the system and has locked out for safety.
Your boiler has repeatedly locked itself out due to low water pressure or a blocked condensate pipe happening too many times in a single day.
Your boiler has registered too many overlapping or conflicting control signals at once, causing it to temporarily lock out for safety.
Your boiler has detected a false flame signal even after the gas supply has been shut off, which causes it to lock out for safety.
Your boiler has detected a problem with how it is burning gas or controlling the gas flow, and has safely shut down to protect your home.
Your boiler has experienced a serious internal software or control board communication fault that requires professional intervention.
Your boiler has encountered an unspecified system error that requires a certified heating engineer to diagnose and resolve.
Your boiler has stopped working because it cannot safely expel combustion gases, meaning you currently have no heating or hot water.
Your boiler has temporarily shut down because it has become too hot inside.
Your boiler is struggling to detect the flow of water through the system, which means it has stopped providing heating and hot water to protect itself.
Your boiler is having trouble measuring the temperature of the water returning to it, so it has safely shut down to prevent overheating.
Your boiler is struggling to detect the temperature of the water coming out of your hot taps, which means it may fail to provide consistent hot water.
Your boiler has detected an issue with the sensor that monitors exhaust gases, meaning it has safely shut down to prevent any risks.
Your boiler has detected that the exhaust gases leaving the flue are dangerously hot and has safely shut down to prevent damage.
Your boiler's main electronic control board has lost or corrupted its internal settings, meaning it no longer knows how to run properly.
Your boiler has detected that the water pressure inside the system is a little higher than ideal, though it is currently just an advisory warning.
Your boiler has detected that the electricity supply coming from your wall socket is too weak to operate the internal components safely.
Your boiler is detecting an issue with the electrical power supply frequency coming into your home.
Your boiler has temporarily stopped working because the water pressure inside the system has dropped too low.
Your boiler is having trouble communicating with the outdoor weather sensor, which means it cannot automatically adjust its temperature based on outside conditions.
Your boiler has temporarily stopped working because the water pressure inside the system has become too high.
Your boiler has lost communication with the internal sensor that monitors water pressure, meaning it cannot confirm if it is safe to fire up.
Your boiler has temporarily locked out because a safety circuit has opened, meaning it cannot safely ignite until the issue is cleared.
Your boiler has detected an issue with its internal safety thermostat configuration, causing it to lock out for your protection.
Your boiler has detected an issue with a safety contact switch, but it is currently continuing to operate normally.
Your boiler has temporarily stopped working because a safety switch has detected that the internal temperature or pressure has reached its safety limit.
Your boiler has lost its proper electronic calibration settings and needs a professional Gas Safe engineer to reset and recalibrate it.
Your boiler has locked itself out for safety because it has been manually reset too many times in a row without solving the underlying issue.
Your boiler is temporarily locking out because it has detected an issue with how the gas is burning inside, meaning it cannot operate safely until checked.
Your boiler's main computer and display screen are failing to talk to each other properly, meaning the system cannot run safely.
Your boiler is currently running an automatic air-clearing cycle to safely remove trapped bubbles from the system.
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BoilerFaultCodes