How much does it cost to fix Atag error code c1 17?

Typical repair cost for the Atag c1 17 fault is £80-150 including labour.

c1 17 High

Atag c1 17 Fault Code

Q: What does the Atag c1 17 fault code mean?

Your boiler has stopped working because the water pressure inside the system has risen too high for it to operate safely.

Also written as C117 — same fault.

The Atag c1 17 fault code means: your boiler has stopped working because the water pressure inside the system has risen too high for it to operate safely.. It appears on 2 Atag models in our database.

Technical description: Water pressure is too high (> 3.0 bar). The boiler is taken out of operation.

Typical repair cost £80-150 (including labour)

DIY fix possible

Locate a radiator in your home with a bleed valve.Place a cloth or small container under the valve.Open the bleed valve slowly to release water until the pressure gauge on the front of the boiler drops to between 1.0 and 1.5 bar.Close the bleed valve tightly once the pressure has returned to the normal range.

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Atag models that show the c1 17 fault code

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

Source

Atag c1 17 fault code information on this page is sourced and cross-checked against the official Atag service / installation manuals for each affected model.

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