Boiler
E229
The E229 error code on a Baxi boiler indicates a fault with the fan or air pressure circuit — it’s a moderate-to-serious fault that almost always requires a Gas Safe registered engineer to resolve safely.
What does this error mean?
E229 signals that your Baxi boiler’s control board has detected a problem with the flue fan or the air pressure proving system. The boiler uses a fan to push combustion gases safely out through the flue, and a pressure switch to confirm this is happening correctly. When the board can’t verify safe airflow, it locks out to prevent dangerous flue gas spillage into your home.
Est. repair cost
£80–£350 depending on the faulty component (pressure switch at the lower end, fan motor at the higher end), all including Gas Safe labour
🔍 Likely causes
🛠️ Step-by-step fix
Perform a boiler reset: press and hold the reset button (usually marked with a flame symbol) for 3–5 seconds. If E229 clears and the boiler fires up normally, monitor it closely for recurrence.
Check your flue terminal outside: look at the external wall or roof outlet where the flue exits. Make sure it isn’t blocked by debris, leaves, or ice — clear any obvious obstruction from outside only.
Check the condensate pipe: if temperatures are below freezing, your condensate pipe (the white plastic pipe that drains outside) may be frozen. Thaw it by pouring warm — not boiling — water over the external section.
Do NOT attempt to access the fan, pressure switch, or any internal boiler components yourself. Gas boilers contain live gas connections and flue components — working on these without a Gas Safe registration is illegal and dangerous.
If the reset doesn’t hold and the fault returns, switch the boiler off at the isolator switch and call a Gas Safe registered engineer — do not keep resetting repeatedly as this can mask a worsening fault.
📞 When to call a professional
Call a Gas Safe registered engineer if the E229 error returns after a single reset, if you cannot identify an obvious external flue blockage, or if your boiler is making unusual noises before locking out. Tell the engineer: ‘My Baxi boiler is showing E229 — I believe it’s a fan or air pressure fault.’ This helps them bring the right parts and saves you time and money on the call-out.
⚖️ Repair or replace?
Fan replacement on a Baxi boiler typically costs £150–£350 including parts and labour; a pressure switch is cheaper at £80–£180 all-in. If your boiler is under 10 years old and otherwise reliable, repair is nearly always worth it. If it’s over 12–15 years old and faults are recurring, a new A-rated combi boiler (£2,000–£3,500 installed) is likely the more cost-effective long-term choice.