BoilerFaultCodes.com
E270 High Lockout

Your boiler has detected that it is overheating because water is not moving through the system properly.

Call an engineer soon

Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Dry fire

What causes this fault?

This fault occurs when the boiler's internal sensors detect a rapid, unsafe rise in temperature because water isn't flowing away from the heat exchanger quickly enough. The most common reasons are a failed internal pump that has stopped spinning or a physical blockage caused by a buildup of sludge and debris in the system pipework.

This issue often surfaces during the first cold spell of autumn when the heating is turned back on after being dormant all summer, causing stuck pump components to fail.

Typical repair cost £120-£350 (including labour)

DIY fix possible

Check that your boiler pressure is between 1 and 1.5 bar on the gaugeEnsure all radiator valves and any isolation valves under the boiler are fully openGently bleed your radiators to remove trapped airReset the boiler to see if the fault clears

Find a Gas Safe engineer

Search the official register for a qualified engineer in your area.

Gas Safe Register →

Protect yourself from future repair bills

A boiler cover plan would cover faults like E270 — no call-out fees, no surprises.

Top rated
OpenFix
Boiler & heating care plans
Get a quote →
Hometree
from £12.95/month
Get a quote →
HomeServe
from £8.00/month
Get a quote →

Affiliate links — we may earn a commission at no extra cost to you.

Baxi GA Range is discontinued — time for a new one?

Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.

UK's #1 online installer
Boxt
Fixed-price online quotes. Next-day installation.
Get a free quote →
Heatable
Instant online boiler quotes from £1,499.
Get a free quote →
iHeat
Fast installation. Price match guarantee.
Get a free quote →

Affiliate links — we may earn a commission at no extra cost to you.

Related fault codes