BoilerFaultCodesIdeal 9.1.2 Fault Code
Also written as 912 — same fault.
The Ideal 9.1.2 fault code means: your heat pump has stopped working because water is not circulating correctly through the outdoor unit.. It appears on 1 Ideal model in our database.
Technical description: No Water Flow, through Outdoor Unit, 10 times in succession
What causes the Ideal 9.1.2 fault?
This fault occurs when the system detects that water is not moving through the outdoor unit quickly enough to safely transfer heat. The most common reasons include a blockage in the pipework, a faulty internal pump, or a build-up of debris in the system filter that is choking the flow.
This issue is more frequent during the first cold snaps of winter when the system is under higher load and any existing debris or pump sluggishness becomes critical.
DIY fix possible
Check that your central heating system pressure is between 1.0 and 1.5 barEnsure all radiator valves and external isolation valves are fully openCheck the outdoor unit for any debris or ice blocking the areaReset the system at the control panel
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Ideal models that show the 9.1.2 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal 9.1.2 fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026