E87 Boiler Fault Code: What It Means on Every Brand

The E87 fault code appears on 2 brands — Baxi and Potterton — and it does not mean the same thing on each. The same two or three characters can signal a pressure problem on one boiler and an ignition fault on another, so identify your brand first and use the table below to jump to the right page.

Up to: Engineer may be needed 2 brands use this code Meaning differs by brand

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 E87 means	Severity	DIY?
BBaxi	The E87 fault code on a Baxi boiler signals an internal communication failure — the boiler's main printed circuit board (PCB) has lost contact with one or more components it needs to talk… Full guide →	Engineer may be needed	No
PPotterton	The E87 fault code on a Potterton boiler indicates that the boiler has lost communication with the room controller or thermostat. Full guide →	Engineer may be needed	Some checks

E87 brand by brand

Baxi E87

The E87 fault code on a Baxi boiler signals an internal communication failure — the boiler's main printed circuit board (PCB) has lost contact with one or more components it needs to talk to, most commonly the gas valve or an external control unit. E87 sits within the E83–E87 family of codes, all of which relate to communication breakdowns within the system. Baxi classifies E87 as a communication error between the PCB and a connected control or component, and in some cases the boiler may attempt to self-reset. If it locks out repeatedly, however, an engineer will need to investigate the root cause rather than simply resetting the unit.

Causes, fixes & costs for Baxi E87 → · All Baxi codes

Potterton E87

The E87 fault code on a Potterton boiler indicates that the boiler has lost communication with the room controller or thermostat. In plain terms, the boiler cannot 'hear' the device that is supposed to tell it when to fire up. This is part of a family of related communication fault codes — E83, E84, E85, E86, and E87 — all of which point to a breakdown in the link between the room controller and the boiler. While the specific sub-code displayed can hint at whether the issue is with pairing, signal quality, or the controller itself, the root cause category is the same across all five. Importantly, E87 is not a gas-safety fault; it will not put your household at risk from gas or carbon monoxide. However, it will typically prevent your heating and hot water from working normally until the communication link is restored.

Causes, fixes & costs for Potterton E87 → · All Potterton codes

Frequently asked questions

Is the E87 fault code the same on every boiler?

No. E87 means different things on different brands — see the table above. Always identify your boiler's brand (it is printed on the front casing) before acting on any advice about the code.

Can I fix a E87 fault myself?

On some brands there are safe homeowner checks first — typically system pressure, the condensate pipe in cold weather, and a single reset. Where the code is a simple pressure or reset condition, that may be all it needs. Never open the boiler casing yourself.

Who should I call about a E87 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.