High
é1 on Remeha Avanta Plus 28c

Your boiler has reached an unsafely high internal temperature, likely because there is not enough water flowing through the system to carry the heat away.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

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

Technical description

Flow temperature is higher than the set maximum temperature. Insufficient water. No through flow. Too much air in the system. Deviation in the flow or return temperature sensor.

Engineer required

This is a high 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 →

Related fault codes

E3View →E7View →E9View →

Related guides you might find useful

Banging / kettling / whistling noise

Each noise points to a different fault.

Read →

Radiators cold at the bottom

Sludge build-up — needs flushing, not bleeding.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →