BoilerFaultCodesGlow-worm 2.5 bar or above Fault Code
Also written as 25BARORABOVE — same fault.
The Glow-worm 2.5 bar or above fault code means: your boiler pressure is too high, which puts unnecessary stress on the internal system components.. It appears on 1 Glow-worm model in our database.
Technical description: Over pressure, the fault display (b) will flash. The pressure must be reduced to 1.5 bar by bleeding a radiator.
DIY fix possible
Locate a radiator in your home that has a bleed valve.Place a small container and cloth underneath the valve to catch water.Use a radiator key to slowly open the valve until water begins to trickle out, watching the boiler's pressure gauge until it drops back to 1.5 bar.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Avoid the next call-out bill
A cover plan would handle faults like 2.5 bar or above: no call-out fees, no surprise bills.
Affiliate links. We may earn a commission at no extra cost to you.
Glow-worm models that show the 2.5 bar or above fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Glow-worm 2.5 bar or above fault code information on this page is sourced and cross-checked against the official Glow-worm service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026