Intergas · HRE, ECO RF & Rapid with iC3 PCB
23S2 temperature rose 10°C within one second
This code applies to Combi Compact HRE 24/18, Combi Compact HRE 28/24, Combi Compact HRE 36/30, Combi Compact HRE 36/40, ECO RF, Rapid 25, Rapid 32. Fault codes narrow down the likely problem, but they do not replace a model-specific diagnosis.
What you can safely check
- Do not remove the boiler case.
- Record the full code and model, then arrange a Gas Safe registered engineer.
How an engineer may fix it
Follow the model-specific fault-finding procedure, test the indicated circuit or component, repair the cause and recommission the appliance.
Manufacturer source: Intergas — HRE, ECO RF & Rapid Parameters and Fault Codes (V10). Checked 15 August 2026. The appliance manual and an engineer’s on-site diagnosis take precedence. Never remove the boiler case yourself.