E161 Boiler Fault Code: What It Means on Every Brand

The E161 fault code appears on 2 boiler brands — Baxi and Potterton — 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 E161 means	Severity	DIY?
BBaxi	The E161 fault code on a Baxi boiler indicates that the boiler's control system has detected a problem with the fan — either it isn't running at the expected speed, or the boiler can't… Full guide →	Lockout — engineer likely	No
PPotterton	The E161 code signals a fan fault on Potterton boilers, closely related to the E160 code which covers the same component. Full guide →	Lockout — engineer likely	No

E161 brand by brand

Baxi E161

The E161 fault code on a Baxi boiler indicates that the boiler's control system has detected a problem with the fan — either it isn't running at the expected speed, or the boiler can't confirm the fan is operating at all. As a safety measure, the boiler locks out and stops firing until the issue is resolved. E161 sits within a family of fan-related fault codes on Baxi boilers (E160, E161, E162, E163), all pointing to fan performance or detection problems. E160 and E161 are the most frequently seen, generally indicating a fan speed or detection failure, whereas E162 and E163 tend to relate to overspeed or abnormal airflow readings. If your display shows any of these codes, the guidance on this page applies.

Causes, fixes & costs for Baxi E161 → · All Baxi codes

Potterton E161

The E161 code signals a fan fault on Potterton boilers, closely related to the E160 code which covers the same component. Your boiler's fan is responsible for drawing combustion air in and expelling harmful flue gases safely out through the flue. Before firing up, the boiler's PCB (printed circuit board) needs confirmation that the fan is spinning correctly. It gets this confirmation via an air pressure switch, which detects the change in internal air pressure that a working fan creates. If that signal never arrives — or arrives erratically — the boiler locks out and displays E161 to prevent potentially dangerous operation. In some cases the boiler may also briefly show related codes such as E131, E151, E152, or E133, because a fan problem can mimic flue or ignition faults; always have an engineer confirm the root cause.

Causes, fixes & costs for Potterton E161 → · All Potterton codes

Frequently asked questions

Is the E161 fault code the same on every boiler?

Broadly, yes — on Baxi and Potterton the E161 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 E161 fault myself?

Not usually. On every brand listed, E161 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 E161 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.