BoilerFaultCodesGrant EE1 Fault Code
The Grant EE1 fault code means: your boiler has sensed a blockage or a pump failure that is stopping water from moving through the system properly.. It appears on 2 Grant models in our database.
Technical description: High pressure – circulating pump failure orcircuit air locked
What causes the Grant EE1 fault?
This fault occurs when water is unable to flow freely through the boiler, leading to a sudden rise in internal pressure. The most common reason is a failed circulating pump that can no longer push water around your radiators, or a large pocket of air trapped within the pipework that is acting as a physical blockage.
This issue is frequently seen in autumn when heating systems are turned back on after being idle all summer, which can cause the internal pump to seize.
DIY fix possible
Check that your radiator valves are openBleed your radiators to remove trapped airEnsure the system pressure gauge is within the correct range (usually 1.0 to 1.5 bar)
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Grant models that show the EE1 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant EE1 fault code information on this page is sourced and cross-checked against the official Grant service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026