Chaffoteaux 215 Fault Code: Causes, Fixes & Repair Costs
What does the Chaffoteaux 215 fault code mean?
Fault code 215 on Chaffoteaux boilers is a cause sub-code linked to a fan-related locking fault (often displayed alongside a C6 lockout error on models that share the Ariston-Chaffoteaux platform). It indicates that the boiler's flue fan has been detected running above its intended speed range. The fan — sometimes called the flue fan or combustion air fan — is responsible for safely expelling waste gases through the flue. When it runs too fast, the control board interprets this as a hazardous condition and locks the boiler out as a precaution. Note that code 214 indicates the fan is not running at all, while code 216 means the fan is running too slowly — all three are variants of the same underlying fan-speed fault family. Because fault codes vary across Chaffoteaux model ranges (Britony, Pigma, Talia, Urbia and others), always cross-reference with your specific boiler's manual if you are unsure.
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 fan motor bearings wear, causing the motor to spin erratically — often faster than the target RPM before eventually slowing down or seizing. This is the most frequently diagnosed cause of code 215 on Chaffoteaux and Ariston-platform boilers.
- Faulty fan speed sensor (tachometer) Common
The fan has a built-in tachometer that sends speed feedback to the PCB. If this sensor develops a fault or its wiring becomes loose or corroded, the PCB receives a false over-speed signal and triggers the lockout even when the fan itself is physically fine.
- Flue or air-intake blockage Sometimes
A partial obstruction in the flue outlet or the fresh-air intake — such as a bird's nest, debris, or a deformed flue terminal — can create abnormal back-pressure that forces the fan to run at an incorrect speed. Worth checking the external flue terminal visually before calling an engineer.
- Wiring fault between fan and PCB Sometimes
Loose terminals, chafed cable insulation, or corrosion on the fan's wiring loom can cause intermittent or erratic speed signals to reach the control board, triggering spurious 215 faults that come and go.
- PCB fault Rare
If the printed circuit board is misreading or incorrectly commanding the fan speed signal — due to component failure or moisture damage — it may generate a 215 code even with a perfectly healthy fan. This is typically only confirmed after the fan and wiring have been ruled out.
How to fix it
- Reset the boiler once DIY safe
Locate the reset button on your Chaffoteaux boiler (usually marked with a flame or reset symbol) and press it firmly, then wait a minute or two for the boiler to attempt a restart. A single reset is reasonable — if the fault clears and the boiler runs normally, monitor it over the next day. If code 215 returns, do not keep resetting, as repeated lockouts can indicate a persistent safety issue.
- Check the external flue terminal for obvious blockages DIY safe
Go outside and inspect the flue outlet on the wall or roof. Look for visible debris, a bird's nest, or a crushed terminal. Do not attempt to dismantle any flue components — if you spot a blockage you cannot safely remove from the outside without touching flue parts, report it to your engineer.
- Do not attempt to work on the fan, wiring, or PCB yourself Gas Safe engineer
The fan assembly, its tachometer wiring, and the PCB are all internal gas-appliance components. Working on them without Gas Safe registration is illegal in the UK and potentially dangerous. Leave all internal investigation to a qualified engineer.
- Call a Gas Safe registered engineer to diagnose and repair the fault Gas Safe engineer
A Gas Safe engineer will test the fan motor for correct speed and operation, inspect the tachometer sensor and its wiring loom for continuity and corrosion, check the flue system internally for obstructions or damage, and test the PCB's fan-control circuit. They will replace whichever component is at fault — most commonly the fan assembly. You can verify any engineer's credentials at GasSafeRegister.co.uk.
Parts you may need
- Flue fan assembly · from £185
- Fan tachometer / speed sensor · from £45
- Fan wiring loom · from £35
- PCB (printed circuit board) · from £280
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 £200–£420, depending on the underlying cause.
Frequently asked questions
Is fault code 215 the same as a C6 error on my Chaffoteaux boiler?
On Chaffoteaux and related Ariston-platform boilers, 215 is a cause sub-code that sits beneath a C6 locking fault. The C6 is the primary lockout category for fan-speed problems, and 215 specifically tells the engineer the fan was detected running too fast. You may see either the C6 alone or the C6 with 215 alongside it, depending on your model's display.
What is the difference between fault codes 214, 215, and 216?
All three are fan-speed cause codes in the same family. Code 214 means the fan is not running at all, code 215 means it is running above its target speed, and code 216 means it is running below target speed. The repair approach is similar for all three — a Gas Safe engineer will inspect the fan motor and tachometer — but the exact fault points to a slightly different failure mode.
Can a frozen condensate pipe cause a 215 fault?
Unlikely. A frozen condensate pipe typically triggers a separate fault code related to the condensate system, not the fan. However, if you have a 215 fault in winter and your boiler is also showing other symptoms, it is worth checking whether the condensate pipe (the small plastic pipe that exits the boiler, usually through an external wall) is frozen and blocked. You can safely thaw it by pouring warm — not boiling — water over the external section. A 215 fault that persists after this still needs an engineer.
My Chaffoteaux boiler is over 10 years old and has a 215 fan fault — should I repair or replace it?
If the repair needed is just a fan assembly (typically £200–£350 including labour), it is usually worth fixing on a boiler that is otherwise in good condition. However, if the PCB also needs replacing — which can add another £250–£400 — or your boiler has a history of breakdowns, the combined cost may approach or exceed the value of the appliance. A modern A-rated combi boiler will also cut your energy bills. Ask your Gas Safe engineer for an honest assessment before committing to an expensive repair on an older unit.