Error E83

Safety first

1) If you smell gas: leave the property immediately, do not operate electrical switches, open windows/doors and call the gas emergency number and a Gas Safe engineer. Do not try to repair the boiler.

2) If you must work near the boiler, switch off the electrical supply at the isolator or fuse spur before touching anything. Do not open the sealed combustion parts or attempt internal repairs.

Initial checks a homeowner can do

1) Note the exact error code, any other codes, and when the code first appeared (after power cut, after work, intermittently etc.). This information helps the engineer.

2) Try a simple reset: either press the boiler reset button (hold for about 5–10 seconds) or switch the boiler off at its isolator, wait 30 seconds and switch it back on. If the code clears and normal operation resumes, monitor it closely — repeated resets indicate an underlying fault.

3) Check external controls: if you have a thermostat, programmer, smart hub or wireless room stat, check they have power/batteries, are set to call for heat, and are correctly paired to the boiler. Replace batteries in wireless devices, and try temporarily bypassing external controls (set the boiler to run from its local controls, if possible) to see if the E83 persists.

4) Check visible wiring and connections you can access without opening the boiler: look at the thermostat wiring in its wiring centre and any accessible connector blocks between devices. Only visually inspect for loose/disconnected cables; do not force connectors or open the boiler cover when powered.

5) Check mains power: confirm the boiler has mains power (display is lit). If the boiler has a fused spur, check the fuse at the spur or consumer unit.

Specific diagnostic and basic fix steps

1) Record any pattern: does E83 occur on start-up, after a power outage, after using controls, or intermittently? That helps isolate whether it’s a wireless pairing, an intermittent wire fault, or board issue.

2) Reset and re-test: after reset, try calling for heat/hot water from the boiler’s local controls. If the boiler runs with local controls but not with the room stat or wireless control, focus on the external control (re-pair wireless unit or check thermostat wiring).

3) Re-pair wireless controls: follow the manufacturer’s re-pairing instructions for your thermostat/system hub. Low batteries and RF interference commonly cause communication faults.

4) If you have a wired thermostat and are competent with low-voltage wiring: isolate power, check the thermostat wires at both ends for firm connections, and ensure no obvious corrosion or damage. If unsure, stop and call an engineer.

5) Do not try to remove or replace the PCB, gas valve, or internal wiring yourself. Those components require specialist testing equipment and must be handled by a Gas Safe registered engineer.

When to call a professional

1) If the E83 code does not clear after a reset and the simple checks above, call a Gas Safe registered engineer. Persistent or repeating E83 faults commonly indicate a failing PCB, a faulty gas valve control circuit, or an intermittent wiring fault that requires diagnostic tools and expertise.

2) If other fault codes appear alongside E83, or the boiler locks out repeatedly, arrange engineer attendance — these symptoms point to internal faults requiring professional repair or replacement.

3) When you call, give the engineer the boiler model, serial number, the exact error code(s), when they occur and what troubleshooting you have already done. This saves time and helps get the right parts and tests prepared.

Final notes

- E83 is primarily a communication/safety control issue. Basic checks and re-pairing or replacing batteries may solve transient problems, but do not attempt internal repairs or component replacements yourself. - Always use a Gas Safe registered engineer for any work on gas appliances, PCBs or gas valves. - Avoid repeatedly resetting the boiler; if the fault returns, power it down and seek professional help.