1 to 9 Low

Remeha 1 to 9 Fault Code

Also written as 1TO9 — same fault.

The Remeha 1 to 9 fault code means: your boiler is operating normally and these numbers represent the current stage of the heating or hot water production process.. It appears on 2 Remeha models in our database.

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description: Operating codes (see Par. 6.3)

DIY fix possible

Check your thermostat is set to the desired temperatureMonitor the display to see if the number changes as the boiler heats upNo action is required as these are status indicators, not error codes

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Remeha models that show the 1 to 9 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Remeha 1 to 9 fault code information on this page is sourced and cross-checked against the official Remeha service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026