BoilerFaultCodesIdeal ERROR CODE 8 Fault Code
Also written as ERRORCODE8 — same fault.
The Ideal ERROR CODE 8 fault code means: your boiler has stopped working because the waste water pipe is likely blocked or frozen, causing water to back up into the unit.. It appears on 2 Ideal models in our database.
Technical description: CONDENSATE BLOCKAGE
What causes the Ideal ERROR CODE 8 fault?
This fault occurs when the liquid waste produced during the heating process cannot drain away from the boiler. The most common reason is a blockage in the drainage pipe or the internal trap, which causes water to back up into the heat exchanger and trigger a safety shutdown. Often, this happens because debris has built up over time or the pipe has become restricted.
This fault is extremely common during freezing winter temperatures, as the external portion of the condensate pipe can freeze, causing a total blockage.
DIY fix possible
Locate the plastic pipe leading from your boiler to the outside of your property.Check if the end of the pipe is blocked by debris or frozen ice.If frozen, pour warm (not boiling) water over the external pipe until the ice melt clears the blockage.Restart the boiler by pressing the reset button.
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Gas Safe Register →Ideal models that show the ERROR CODE 8 fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal ERROR CODE 8 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