E.02-.17 Boiler Fault Code: What It Means on Every Brand

The E.02-.17 fault code appears on 2 boiler brands — Baxi and Remeha — and on all of them it points to the same kind of problem. The details still differ by brand (thresholds, sub-codes, reset procedure), so use the table below to jump to the page for your boiler.

Lockout — engineer likely 2 brands use this code

Which brand is your boiler?

The brand is printed on the front casing. Tap your brand for the full causes, fixes and repair costs.

Brand	What E.02-.17 means	Severity	DIY?
BBaxi	The E.02-.17 code indicates a permanent, locking communication breakdown between the boiler's gas valve and its PCB (Printed Circuit Board). Full guide →	Lockout — engineer likely	No
RRemehashown as E.02.17	The E.02.17 code (also shown as E02.17) means the boiler's main control board has lost communication with its internal safety sub-unit — known as the CU-GH or CSU. Full guide →	Lockout — engineer likely	No

E.02-.17 brand by brand

Baxi E.02-.17

The E.02-.17 code indicates a permanent, locking communication breakdown between the boiler's gas valve and its PCB (Printed Circuit Board). Because the PCB can no longer reliably send or receive signals to and from the gas valve, the boiler shuts itself down and will not attempt to restart on its own — it stays locked out until an engineer diagnoses and resolves the underlying fault. This is the permanent version of the related H.01.00 code, which flags only a temporary communication hiccup that can sometimes clear itself. E.02-.17 will not clear on its own and is not safe to keep resetting without identifying the root cause.

Causes, fixes & costs for Baxi E.02-.17 → · All Baxi codes

Remeha E.02.17

The E.02.17 code (also shown as E02.17) means the boiler's main control board has lost communication with its internal safety sub-unit — known as the CU-GH or CSU. These two components constantly exchange data to confirm that all safety-critical processes are running correctly. When that dialogue times out or breaks down entirely, the boiler locks out as a precaution. This is an internal electronic fault rather than a problem with gas supply, water pressure, or pipework, so the fix almost always involves an engineer checking wiring and potentially replacing the CU-GH printed circuit board.

Causes, fixes & costs for Remeha E.02.17 → · All Remeha codes

Frequently asked questions

Is the E.02-.17 fault code the same on every boiler?

Broadly, yes — on Baxi and Remeha the E.02-.17 code points to the same class of fault, and the recommended response is similar. Model-specific details such as sub-codes and reset procedures still vary, so follow the page for your own brand.

Can I fix a E.02-.17 fault myself?

Not usually. On every brand listed, E.02-.17 points to a fault that needs a suitably registered engineer to diagnose and repair. A single reset to rule out a transient glitch is reasonable; repeated resets are not.

Who should I call about a E.02-.17 fault?

For gas boilers, a Gas Safe registered engineer — it is a legal requirement for any work on the appliance. If you smell gas at any point, leave the property and call the National Gas Emergency line on 0800 111 999.

General guidance only — not a substitute for professional advice, and not certified by a registered engineer. Any work on a gas appliance must be carried out by a Gas Safe registered engineer. If you smell gas, call 0800 111 999.