Low
25 on Sime Murelle EV HE Combi

Your boiler is having trouble communicating with the temperature sensor linked to your solar water heating system, which may prevent the solar panel integration from working correctly.

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

SOLAR S2 BOILER PROBE FAILURE

Shared across the Murelle EV HE 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 →

Avoid the next call-out bill

A cover plan would handle faults like 25: 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

All 71 fault codes on the Murelle EV HE Combi

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

Related guides you might find useful