Error E384

Safety first

- If you smell gas: do not attempt any checks on the boiler. Turn off gas at the meter if safe to do so, turn off electrical supply to the property, get everyone out, ventilate the area and call your gas emergency number immediately.

- If you do not smell gas, still treat any flame/ignition fault as potentially serious. Do not open the boiler casing or attempt to work on gas or wiring unless you are a Gas Safe registered engineer.

Initial homeowner checks (safe, non-invasive)

1. Note the behaviour: has the boiler been attempting to fire and then locking out? Does it display E384 continuously or intermittently? Has anything else changed (power cut, low pressure, frozen condensate pipe)?

2. Check gas supply: verify other gas appliances (hob) work. If you have a prepayment gas meter, ensure it has credit. If other appliances don’t work, call your gas supplier before arranging boiler repair.

3. Check electrical supply: ensure the boiler display/power is on and the fuse/trip hasn't operated.

4. Check water pressure: look at the pressure gauge. Aim for about 1–1.5 bar for most systems. If pressure is very low (well below 1 bar), top up the system following the manufacturer’s instructions and then try a reset. Low pressure can cause unrelated faults to appear.

5. Check vents and flue: ensure the outside flue terminal and any air vents are not blocked by debris or snow. Also check for a frozen condensate pipe in cold weather and thaw it if frozen.

Reset procedure (only one or two attempts)

1. Locate the reset button on the front panel (or the selector set to R on some models).

2. Press and hold the reset for the time specified in your manual (typically 3–10 seconds) until the boiler attempts to restart.

3. Wait and observe: if the boiler restarts and runs normally, monitor for reoccurrence. If E384 returns immediately or after a short time, do not keep repeatedly resetting.

Further diagnostic steps you can safely perform

1. Power-cycle: switch the boiler off at the mains for 60 seconds then back on, then try a reset. This can clear temporary communication faults.

2. Visual external inspection: with the boiler off and cooled, look for any obviously loose or damaged external wiring to any visible connectors or external controls (do not open the boiler casing). Tighten loose external terminal screws (only if accessible without opening the appliance).

3. Check for pattern: note if the fault appears only when calling for DHW or central heating, or both. That information is useful to the engineer and can indicate whether the fault is in the ignition/flame detection circuit or related to flow/temperature sensors.

When to stop and call a professional

- Call a Gas Safe registered engineer if the error persists after the simple checks and a reset, if the boiler locks out repeatedly, if you detect any gas smell, or if you are unsure about any step. E384 can indicate the ionisation electrode, ignition module, gas valve, wiring or the PCB is at fault — components that must be tested and repaired by a qualified engineer.

Information to give to the engineer

- Exact error code (E384), whether it is continuous or intermittent, whether it appears on demand for heating, hot water or both, recent power outages, any low-pressure incidents, and whether you completed the reset and what happened. Mention if you checked gas supply, pressure and flue/condensate.

Summary

- Safe DIY: basic checks (gas supply, mains power, pressure, flue/condensate), one controlled reset and power-cycle, and non-invasive visual checks.

- Professional required: any internal inspection, ignition/flame electrode replacement, PCB/ignition module, gas valve or wiring repairs — contact a Gas Safe registered engineer. Do not repeatedly reset the boiler and never attempt gas/electrical repairs yourself.