Chaffoteaux 213 Fault Code: Causes, Fixes & Repair Costs
What does the Chaffoteaux 213 fault code mean?
Fault code 213 on Chaffoteaux boilers sits within the 210-series of codes, which relate to the heating return circuit sensor. Code 213 specifically indicates that the boiler's control board has detected a short circuit or out-of-range reading from the return NTC thermistor — the sensor responsible for monitoring the temperature of water as it comes back into the boiler from the heating system. When this sensor reports an implausible value (zero or near-zero resistance suggests a short circuit; infinite resistance suggests an open circuit or broken connection), the boiler locks out as a safety measure. Related codes in the same series include 211 (return sensor reading too low or open circuit) and 212 (return sensor reading anomaly); 213 is the short-circuit variant. The boiler will not fire until the fault is cleared.
General guidance only — not a substitute for professional advice, and not certified by a Gas Safe engineer. Always have your specific appliance assessed by a qualified professional. Any gas work must be carried out by a Gas Safe registered engineer. If you smell gas or suspect carbon monoxide, leave the property and call the National Gas Emergency line on 0800 111 999.
Common causes
- Faulty return NTC thermistor Common
The return temperature sensor itself has failed, producing a resistance reading that is outside the expected range (approximately 8.1–8.6 kΩ at 25°C). A reading of 0 Ω confirms a short circuit within the sensor body, which is the most common trigger for code 213.
- Damaged or corroded wiring and connectors Common
The wiring loom running between the return sensor and the PCB can develop faults over time — particularly at the connector ends where corrosion, moisture ingress, or physical damage can cause the circuit to short. A damaged connector will mimic a failed sensor and produce the same code.
- Moisture on sensor or PCB connector Sometimes
Condensation or a minor water leak near the sensor connector can temporarily bridge the contacts, creating a short-circuit condition. Once the moisture evaporates the fault may clear, but if the root cause of the moisture is not fixed the fault will return.
- Faulty PCB (control board) Rare
If the sensor and all associated wiring test correctly but code 213 persists, the PCB's sensor-monitoring circuit may have failed. Visual signs of board damage — scorched components, swollen capacitors, or discoloured tracks — support this diagnosis, though PCB faults can also be invisible to the naked eye.
How to fix it
- Reset the boiler once or twice DIY safe
Press and hold the reset button on the boiler's front panel as described in your user manual. A single short-circuit spike can occasionally trigger a spurious lockout. If the boiler fires up and runs normally after one or two resets, monitor it closely. If code 213 returns within a short period, move on to further investigation and do not keep resetting — repeated lockouts indicate a genuine fault.
- Check system pressure DIY safe
Look at the pressure gauge on the boiler front. It should read between 1.0 and 1.5 bar when the heating is cold. If it has dropped below 1 bar, top it up via the filling loop until it reaches approximately 1.2 bar, then attempt another reset. Low pressure alone is unlikely to cause code 213, but it is a quick, safe check worth doing before calling an engineer.
- Check for obvious moisture around the sensor area DIY safe
With the boiler switched off and cooled down, visually inspect around the boiler casing for signs of a water leak or heavy condensation near pipework. Do not open the boiler casing or touch any internal components. If you can see dripping water or significant damp, note this when you call an engineer — it may be the root cause of the connector short.
- Engineer to test the return NTC sensor resistance Gas Safe engineer
A Gas Safe registered engineer will disconnect the return NTC thermistor and measure its resistance with a calibrated multimeter. At approximately 25°C, a healthy Chaffoteaux return sensor should read around 8.1–8.6 kΩ. A reading close to 0 Ω confirms a short circuit in the sensor; an open-circuit (infinite) reading confirms a break. Either result means the sensor needs replacing.
- Engineer to inspect wiring loom and connectors Gas Safe engineer
The engineer will also check the wiring between the sensor and the PCB for signs of chafing, melted insulation, corroded pins, or moisture damage. A damaged wire can be repaired or the loom section replaced; corroded connectors should be cleaned or renewed. This step is often done alongside the sensor test and adds little time to the job.
- Engineer to replace the return NTC thermistor if faulty Gas Safe engineer
If the sensor tests outside specification, the engineer will fit a new return NTC thermistor. The compatible Ariston/Chaffoteaux thermistor (part reference 61000733) is a low-cost part, typically under £20 including VAT from UK spare parts suppliers. Once fitted and connected, the engineer will clear the fault, fire the boiler, and verify the return temperature reading is being reported correctly.
- Engineer to assess and replace the PCB if the fault persists Gas Safe engineer
If the sensor and wiring both test correctly but code 213 continues to appear, the PCB's sensor input circuit is likely faulty. The engineer will inspect the board for visible damage and, if required, fit a replacement PCB matched to the boiler model. This is the most expensive outcome and is relatively uncommon for this fault code.
- Call a Gas Safe registered engineer Gas Safe engineer
If the fault does not clear after a reset and basic pressure check, book a Gas Safe registered engineer to diagnose and resolve the fault. You can verify any engineer's credentials at gassaferegister.co.uk. Annual boiler servicing can help catch sensor and wiring issues before they cause a breakdown.
Parts you may need
- Chaffoteaux return NTC thermistor (ref. 61000733) · from £15
- Sensor wiring harness / connector pigtail · from £20
- Chaffoteaux PCB (model-specific) · from £180
The exact spare depends on your boiler's GC number (on the data badge). Check this against the part before buying.
Typical repair cost
Expect to pay roughly £100–£250, depending on the underlying cause.
Frequently asked questions
Is Chaffoteaux fault code 213 dangerous?
Code 213 is a sensor fault rather than a gas or combustion safety issue, so it does not indicate an immediate danger such as a gas leak or carbon monoxide risk. However, the boiler locks out and will not provide heating or hot water until the fault is fixed. You should still have it looked at promptly by a Gas Safe registered engineer, particularly in cold weather.
Can I fix fault code 213 myself?
The only checks a homeowner can safely carry out are resetting the boiler (once or twice), checking the system pressure and topping up via the filling loop if needed, and looking for obvious signs of moisture or a water leak around the boiler exterior. Any work inside the boiler — testing or replacing the sensor, inspecting wiring, or working on the PCB — must be carried out by a Gas Safe registered engineer. Attempting internal repairs yourself is unsafe and could invalidate your warranty or home insurance.
How much does it cost to fix a Chaffoteaux 213 fault in the UK?
For most people this fault is resolved by replacing the return NTC sensor, which is a cheap part (around £10–£20). Combined with a standard Gas Safe engineer callout and labour, the total is typically £100–£200. If the wiring loom also needs attention, costs sit toward the upper end of that range. In the less common scenario where the PCB is at fault, expect to pay £250–£450 for a board replacement including labour. Always get at least two quotes for PCB work, and consider the age and overall condition of the boiler before committing to an expensive repair.
What is the difference between Chaffoteaux fault codes 211, 212, and 213?
All three codes are in the 210-series, which covers the heating return circuit temperature sensor. Code 211 typically indicates the sensor is reading an abnormally low temperature or an open circuit (broken connection or failed sensor with very high resistance). Code 212 indicates a general sensor anomaly or out-of-range reading. Code 213 specifically points to a short circuit in the return sensor circuit — where the resistance has collapsed toward zero, suggesting the sensor or its wiring has shorted. The diagnostic and repair approach is very similar for all three: an engineer tests the sensor resistance and inspects the wiring before deciding whether to replace the sensor, the loom, or in rare cases the PCB.