Are there any specific boiler brands or models where E125 is a common or unique error, or is it a generic low-pressure code?

Error code E125 is not specific to one boiler brand or model; rather, it's a common error code used across various manufacturers (e.g., Vaillant, Baxi, Worcester Bosch often have similar low-pressure codes, though the exact number might vary slightly) to indicate low system water pressure. While the exact numerical code might differ, the underlying meaning of insufficient pressure in the heating circuit is widely consistent. Always consult your specific boiler's manual to confirm the precise meaning of E125 for your model, as manufacturers can sometimes assign unique codes or have specific troubleshooting steps.