📊 Baxi Boiler Fault Codes — Full Reference
| Code | Meaning | DIY Fix? | Urgency |
|---|---|---|---|
| E119 | Low water pressure | ✅ Repressurise | 🟡 Low |
| E133 | Gas valve / ignition fault | Check gas, reset once | 🔴 Urgent |
| E168 | Gas valve fault | No — call engineer | 🔴 Urgent |
| E28 | Flue / air pressure fault | No — call engineer | 🔴 Urgent |
| E50 | DHW NTC sensor fault | No — call engineer | 🟠 Same day |
| E110 | Boiler overheat / safety stat | No — call engineer | 🔴 Urgent |
| E125 | Pump fault / no flow | No — call engineer | 🟠 Same day |
| E160 | Fan fault | No — call engineer | 🔴 Urgent |
| E131 | Temperature sensor fault | No — call engineer | 🟠 Same day |
| E20 | Return NTC sensor fault | No — call engineer | 🟠 Same day |
💧 E119 — Low Water Pressure (Most Common)
E119 is the most common Baxi fault code and simply means the water pressure in the system has dropped below the minimum level required.
How to fix E119 — repressurise your Baxi boiler:
- Switch the boiler off at the programmer or thermostat
- Locate the filling loop — usually a silver braided hose under the boiler
- Slowly open the valves (turn anti-clockwise) until you hear water entering
- Watch the pressure gauge — stop at 1.2 bar
- Close both valves and switch the boiler back on
- Press Reset to clear the E119 code
If E119 keeps coming back within a few weeks, you have a leak causing the pressure to drop. FE Maintenance can trace and fix any leak — call 020 8445 1303.
🔥 E133 — Ignition / Gas Valve Fault
E133 means the boiler has failed to ignite successfully. It's one of the more serious Baxi fault codes and requires careful attention.
What to check first:
- Check gas supply — does the hob or gas fire work?
- If no gas at all — call National Gas Emergency: 0800 111 999
- Check if gas meter supply is on (lever parallel to pipe = on)
- Press Reset once and monitor
E133 that returns after reset indicates a component failure. Common causes: faulty spark ignition electrode, defective gas valve, or PCB fault. Do not keep resetting — call FE Maintenance on 020 8445 1303.
⚠️ E168 — Gas Valve Fault
E168 is a more serious fault indicating the gas valve is not opening correctly or is receiving incorrect signals from the PCB.
This fault requires a Gas Safe engineer — do not attempt to repair the gas valve yourself.
Possible causes:
- Faulty gas valve (modulating valve failure)
- PCB sending incorrect voltage to gas valve
- Wiring fault between PCB and gas valve
- Gas valve solenoid failure
E168 should be treated as urgent. A faulty gas valve can be a safety risk. Turn the boiler off and call FE Maintenance on 020 8445 1303 for same-day repair.
💷 Baxi Boiler Repair Costs in London
| Fault | Typical Repair Cost |
|---|---|
| Low pressure fix (E119) | £80 – £130 |
| Ignition electrode (E133) | £100 – £180 |
| Gas valve replacement (E168) | £220 – £380 |
| PCB replacement | £220 – £420 |
| Fan replacement (E160) | £150 – £280 |
| Pump replacement (E125) | £180 – £300 |
| Temperature sensor | £90 – £180 |
Frequently Asked Questions
E119 on a Baxi boiler means the water pressure is too low. The boiler needs a pressure of at least 1 bar to operate safely. You can fix this yourself by repressurising using the filling loop under the boiler until the gauge reads 1.2 bar. If pressure keeps dropping, call FE Maintenance on 020 8445 1303.
E133 indicates ignition failure — the boiler tried to light but couldn't. Check your gas supply first (try the hob). If gas is fine, reset once. If E133 returns, there's a component fault — ignition electrode, flame sensor, or gas valve — that needs a Gas Safe engineer. Call FE Maintenance on 020 8445 1303.
E168 indicates a gas valve fault which should be treated as urgent. Turn the boiler off and do not attempt to reset repeatedly. Call FE Maintenance on 020 8445 1303 for same-day diagnosis. A faulty gas valve can be a safety hazard if ignored.
Most Baxi boilers have a Reset button on the front panel or accessible through the casing. Press and hold for 3-5 seconds. Some models require you to press the Reset and a function button simultaneously — check your boiler manual. If the fault returns immediately, call FE Maintenance.
A well-maintained Baxi boiler typically lasts 12-15 years. Baxi offers warranties of 5-10 years on their boilers (varies by model) provided they are serviced annually by a Gas Safe engineer. FE Maintenance services and repairs all Baxi boiler models across London.
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