Low
External probe faulty on Ferroli Arena 30 C

Your boiler's outside temperature sensor has developed a wiring or component fault, meaning it can no longer accurately read the outdoor weather.

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

Sensor damaged or wiring short-circuited

From this model's manual
Verified against the Ferroli/Ferroli Arena 30 C installation & service 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 External probe faulty: 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

A06View →F37View →

All 18 fault codes on the Arena 30 C

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

ADomestic hot water sensor faultyExcessive central heating outlet temperatureExcessive central heating return temperatureFFailed burner assembly ignitionFan faultFlue gas sensor faultyFlue safety device interventionHigh flue gas temperatureInsufficient water system pressureMicroprocessor faultyNo communication between main board and ignition devicesNo flame following the ignition phaseOutlet sensor faultyReturn sensor faultySafety thermostat activation

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 →