Chaffoteaux 715 Fault Code: Causes, Fixes & Repair Costs
What does the Chaffoteaux 715 fault code mean?
If your Chaffoteaux boiler is showing what appears to be '715', it is most likely being misread from a two-part display or a combination of LED indicators rather than a single numeric fault code. Older Chaffoteaux models such as the Britony Combi SE use flashing LED patterns across numbered indicators rather than a digital screen, so a sequence that looks like '7', '1', '5' may actually be two separate signals displayed in quick succession. On newer digital-display models (Pigma, Urbia, Minima HE), codes are shown as two flashing digits — so '715' may be the display cycling through '7' then '15', pointing to a fan or air pressure switch fault. The underlying fault most commonly associated with these indicator patterns is a problem with the fan or air pressure switch circuit, though ignition failure and PCB faults are also possible. Check your model data plate (inside the boiler casing or on the front panel) and cross-reference your exact model's manual — available free on ManualsLib — before attempting any action. If in any doubt, contact a Gas Safe registered engineer with your full model name and the exact code you see on screen.
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
- Fan or air pressure switch fault Common
The boiler fan is either running without triggering the air pressure switch, or the switch is failing to reset after the fan stops. Either condition causes the boiler to lock out as a safety measure. A blocked fan, dirty pressure switch, or blocked flue outlet are common culprits.
- Frozen or blocked condensate pipe Common
In cold weather the external condensate pipe (a white plastic pipe exiting through an outside wall) can freeze solid, preventing the boiler from draining condensate. This triggers a lockout that can be misread as a fan or ignition fault.
- Ignition or flame detection failure Sometimes
The boiler attempts to light but cannot establish a stable flame. This may be caused by a faulty or dirty ignition electrode, a worn ionisation lead, a weak gas supply, or a partially closed gas valve.
- PCB (printed circuit board) fault Sometimes
The PCB controls every major boiler function. Age-related wear, water ingress from internal leaks, damaged solder joints, or excessive vibration can all cause the PCB to misread sensor signals or fail to command components correctly, resulting in repeated lockouts or a blank display.
- Misidentified code due to display type Common
On older LED-indicator models, the sequence of lights being displayed may be misread as a three-digit number. On digital models, the display alternates between two separate digits. If the code you are seeing does not appear in your model's manual, this is the most likely explanation.
How to fix it
- Identify your exact Chaffoteaux model DIY safe
Open the boiler casing or check the front panel for the data plate, which shows the full model name and serial number. Different Chaffoteaux models display fault codes in completely different ways — knowing your exact model is essential before interpreting any code.
- Check your model-specific manual DIY safe
Download the correct manual from ManualsLib.com or FreeBoilerManuals.com using your model name. Confirm whether your boiler uses LED flash patterns or a digital two-digit display, and look up what '7 15' or your specific indicator combination means for your model.
- Check that your gas supply is on DIY safe
Confirm that other gas appliances in your home (hob, gas fire) are working normally. If there is no gas supply at all, check your prepayment meter credit, and contact your gas supplier if the supply appears to be off at the meter.
- Check the system pressure DIY safe
Look at the pressure gauge on the boiler — it should read between 1.0 and 1.5 bar when cold. If it reads below 0.5 bar, top up the pressure using the filling loop (a braided flexible hose beneath the boiler) until it reaches approximately 1.2 bar, then close the filling loop valves.
- Inspect the external condensate pipe in cold weather DIY safe
Locate the white plastic condensate pipe where it exits through an external wall or terminates outside. If it feels solid or has visible ice around the outlet, it has likely frozen. Gently thaw it by pouring warm (not boiling) water along its length, then reset the boiler once.
- Attempt a single boiler reset DIY safe
Press the reset button (or hold it for the duration specified in your model's manual) once, then wait several minutes to see if the boiler fires successfully. If the fault reappears after one or two resets, stop resetting — repeated resets without resolving the underlying fault can cause further damage.
- Call a Gas Safe registered engineer Gas Safe engineer
If the fault persists after the checks above, a Gas Safe registered engineer must inspect the boiler. They will check the fan, air pressure switch, flue integrity, ignition electrode and leads, gas valve operation, and PCB. Ask them to confirm the exact fault code meaning for your specific model. Do not attempt to open the boiler casing or touch any internal components yourself.
Parts you may need
- Boiler fan / flue fan assembly · from £120
- Air pressure switch · from £45
- Ignition electrode · from £35
- Ionisation / flame detection lead · 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 £150–£380, depending on the underlying cause.
Frequently asked questions
Why does my Chaffoteaux boiler show '715' but I can't find it in the manual?
Chaffoteaux boilers use different fault-display systems depending on their age. Older models like the Britony Combi SE use numbered LED indicators rather than a digital screen, so what appears to be '715' may actually be a sequence of two separate indicator lights being displayed one after the other. On newer digital-display models, codes are shown as two alternating digits — for example, the display may be cycling between '7' and '15'. Always identify your exact model name from the data plate and download the correct manual to interpret the code accurately.
Can I fix a Chaffoteaux fan or air pressure switch fault myself?
Homeowners can safely carry out a few checks: confirming the gas supply is on, topping up boiler pressure via the filling loop, thawing a frozen condensate pipe in cold weather, and performing a single reset. However, inspecting or replacing the fan, air pressure switch, ignition components, gas valve, or PCB all require a Gas Safe registered engineer. Working on these components without Gas Safe registration is both illegal and dangerous.
How much does it typically cost to repair a Chaffoteaux fan or ignition fault in the UK?
For most homeowners, a fan replacement or ignition component repair on a Chaffoteaux boiler costs between £150 and £380 including parts and labour. A diagnostic call-out is typically £60–£100, which is often applied against the final repair bill. PCB replacement is a more expensive job — usually £450–£700 — and on a boiler that is more than 10 years old it is worth comparing that cost against a full boiler replacement before committing to the repair.
Is it safe to keep resetting my Chaffoteaux boiler when it shows this fault?
No. You can try one or two resets to see if the fault clears after a straightforward cause such as a frozen condensate pipe, but if the boiler locks out again you should stop resetting and call a Gas Safe engineer. The lockout is a safety mechanism — repeatedly overriding it without fixing the underlying problem can cause further damage to components and, in the case of ignition or flue faults, poses a safety risk.