Emergency
F40 on ECA Confeo Premix HM

Your boiler has shut down because there is too much water in the system, causing the pressure to rise above a safe limit.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

High Water Pressure Fault (blocking) — water pressure sensor detects high water pressure (2.9 bar); check water pressure; turn off device and restart; if persists notify ECA authorised service

Shared across the Confeo Premix P range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

Find a Gas Safe engineer
Search the official register →
Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like F40: no call-out fees, no surprise bills.

Approved partner
Domestic Appliance Guard
Unlimited call-outs, 24/7 helpline, no price-hike promise
Get a quote →

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

Related fault codes

F41View →F47View →

All 38 fault codes on the Confeo Premix HM

Seeing a different code? Every code this model can display, in one place.

E01E02E03E15E16E17E18E33E35E38E44E64E65E80E82E83E98E99F05F07F10F13F34F36F37F39F41F42F43F47F49F50F51F52F53F81F201

Related guides you might find useful

Boiler keeps losing pressure

Six most common causes of dropping pressure.

Read →

What pressure should my boiler be?

1 to 1.5 bar when cold on most UK boilers, from the manuals.

Read →

Low pressure: how to repressurise

Step by step using the filling loop.

Read →