Low
Er 08 on Biasi Advance Plus

Your boiler is struggling because it has lost the signal from the weather sensor installed outside your home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

What the manual says

Manufacturer manual

Faulty external temp. probe NTC

Shared across the Advance Plus 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 fault requires 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 Er 08: 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

Er 04View →Er 05View →

All 35 fault codes on the Advance Plus

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

An 11Er 01Er 01 + RESETEr 02Er 02 + RESETEr 03Er 03 + RESETEr 04Er 04 +Er 05Er 05 +Er 06Er 06 +Er 07Er 07 +Er 08 +Er 09Er 09 +Er 10Er 10 + RESETEr 11Er 12Er 12 +Er 13Er 13 +Er 14Er 14 +Er 14 + RESETEr 19Er 19 +Er 25Er 25 + RESETEr 69Li 01

Related guides you might find useful

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →

Boiler service cost

What a UK service costs and what a proper one includes.

Read →