Chaffoteaux 216 Fault Code: Causes, Fixes & Repair Costs
What does the Chaffoteaux 216 fault code mean?
Fault code 216 is a locking fault — meaning the boiler shuts down and requires a manual reset — triggered when the boiler's control board detects that the fan is operating outside its permitted speed range. The PCB continuously monitors fan speed via a feedback signal; if the fan spins too slowly or too quickly relative to what the board has requested, it raises this error and locks the boiler out as a safety measure. Code 216 sits within the C6 fan-fault group (alongside code 215), which covers fan speed deviations. The boiler will not restart on its own; a reset is needed, and if the root cause is not resolved the lockout will return.
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
- Worn or failing fan motor Common
Over time the motor windings can burn out and the bearings deteriorate, causing the fan to spin erratically or not reach the target speed. This is the single most common root cause of a 216 lockout on Chaffoteaux boilers.
- Faulty Hall effect sensor Common
The Hall sensor is built into the fan motor and sends the speed-feedback signal to the PCB. If it develops a fault, the board receives a corrupted or absent reading and triggers the 216 error — even if the fan itself is mechanically sound.
- Wiring or connector fault Sometimes
Loose, corroded, or damaged connectors on the fan power supply or signal wires can interrupt the speed-feedback circuit, making a healthy fan appear to be running out of range.
- Blocked flue or fan intake Sometimes
A partial obstruction at the flue terminal (bird nests, leaves, frost build-up) or inside the fan casing restricts airflow, forcing the fan to work harder or stall, pushing its speed outside tolerance.
- External draught affecting fan speed Sometimes
Strong wind entering the flue terminal can create back-pressure that either slows the fan below its target speed or causes erratic speed readings that confuse the PCB.
- PCB fault Rare
If the control board itself is not correctly generating the fan speed demand signal or interpreting the feedback, it can report a 216 error even when the fan and sensor are in good condition.
How to fix it
- Check that other gas appliances in the property are working normally DIY safe
Turn on a gas hob or check another gas appliance. If nothing gas-powered is working, the issue may be with the gas supply rather than the boiler. Contact your gas supplier before proceeding.
- Inspect the external flue terminal for obvious obstructions DIY safe
Only if the terminal is safely visible from ground level — do not use ladders. Look for bird nests, accumulated debris, heavy frost, or anything visibly blocking the outlet. If you spot a blockage you can safely remove from ground level (e.g. with a broom handle), clear it before attempting a reset.
- Reset the boiler once and observe DIY safe
Press and hold the reset button as described in your boiler's handbook. Wait at least 60 seconds after the reset attempt. If the boiler fires up and runs without relocking, monitor it over the next hour. If the 216 code returns — even once — do not reset again; repeated resets on a fan fault will not fix the underlying problem and can mask a developing safety issue.
- Engineer: verify fan operation and measure actual speed against the PCB demand Gas Safe engineer
A Gas Safe engineer should confirm whether the fan starts when commanded and use diagnostic tools to compare the actual fan speed with the value the PCB is requesting. A significant discrepancy confirms a fan or sensor fault rather than a wiring issue.
- Engineer: test the Hall sensor signal and inspect wiring Gas Safe engineer
The engineer should check the Hall sensor output with a multimeter or oscilloscope, inspect all connectors on the fan wiring loom for corrosion or looseness, and test wiring continuity back to the PCB. A faulty sensor reading can be resolved by replacing the fan assembly.
- Engineer: inspect the fan motor, impeller, and flue pathways Gas Safe engineer
The motor and impeller should be examined for physical wear, heat damage, or debris. The air-intake and flue-gas paths should be checked for partial blockages. If bearings are noisy or the impeller is damaged, a full fan replacement is usually more cost-effective than a repair.
- Engineer: replace fan assembly if required Gas Safe engineer
Where the motor, bearings, or Hall sensor are at fault, fitting a new manufacturer-approved fan unit is the standard remedy. Labour costs for fan motor repair are typically comparable to outright replacement, so a new unit is usually recommended for long-term reliability.
- Engineer: assess the PCB if the fault persists after fan replacement Gas Safe engineer
If a new fan and confirmed good wiring do not clear the 216 code, the PCB may be misreading the speed signal. The board will need bench testing or replacement by a Gas Safe registered engineer.
- Call a Gas Safe registered engineer if the fault has not cleared Gas Safe engineer
If the boiler re-locks after a single reset attempt, or if you have not been able to identify an obvious flue obstruction, contact a Gas Safe registered engineer. Do not continue resetting — arrange a professional inspection as soon as possible, especially during cold weather.
Parts you may need
- Boiler fan assembly (motor and impeller) · from £120
- Integrated Hall effect sensor (if sold separately) · from £35
- Fan wiring loom / connector set · from £25
- PCB (printed circuit board) · from £220
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 £120–£350, depending on the underlying cause.
Frequently asked questions
Can I keep resetting my Chaffoteaux boiler to clear a 216 fault?
One reset attempt is reasonable to rule out a momentary glitch. If the boiler relocks with code 216 a second time, repeated resets will not solve the problem — the fan or its control circuit has a genuine fault that needs a hands-on inspection. Continuing to reset can also mask a developing issue, so arrange an engineer visit rather than cycling the reset button.
Is a 216 fault dangerous — can I still use hot water?
The boiler locks itself out precisely because the fan is not operating correctly, and the fan is essential for safely removing combustion gases from your home. You should not attempt to bypass the lockout or force the boiler to run. Until a Gas Safe engineer confirms the fan is working within its correct speed range, treat the boiler as out of service and contact an engineer promptly.
What is the difference between Chaffoteaux fault codes 215 and 216?
Both codes fall within the C6 fan-fault category. Code 215 indicates the fan has been detected running above its target speed range, while code 216 means it is running too slowly or not reaching the requested speed. In practice, the diagnostic and repair process is very similar for both — the engineer will check the fan motor, Hall sensor, wiring, and PCB in the same way regardless of which sub-code is displayed.
How much does it cost to fix a Chaffoteaux 216 fault in the UK?
For most homeowners, the repair falls in the region of £120–£350. A minor fix such as clearing a blockage or resolving a wiring connector issue sits at the lower end, while a full fan assembly replacement including labour typically costs £200–£350 depending on your region and the specific Chaffoteaux model. If the PCB turns out to be at fault, that component alone can add £180–£400 to the bill — but PCB replacement is a less common outcome for a 216 code. Prices in London and the South East tend to be higher than in northern regions.