How much does it cost to fix Chaffoteaux error code 50 70 80?

Typical repair cost for the Chaffoteaux 50 70 80 fault is £120-220 including labour.

50 70 80 High

Chaffoteaux 50 70 80 Fault Code

Q: What does the Chaffoteaux 50 70 80 fault code mean?

Your boiler is failing to detect the temperature of the water entering the system, which is preventing it from heating your home safely.

Also written as 507080 — same fault.

The Chaffoteaux 50 70 80 fault code means: your boiler is failing to detect the temperature of the water entering the system, which is preventing it from heating your home safely.. It appears on 2 Chaffoteaux models in our database.

Technical description: Thermistor inlet heating open

Typical repair cost £120-220 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Chaffoteaux models that show the 50 70 80 fault code

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

Source

Chaffoteaux 50 70 80 fault code information on this page is sourced and cross-checked against the official Chaffoteaux service / installation manuals for each affected model.

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