BoilerFaultCodesYour boiler has shut down because the internal gases have become too hot, which is a safety measure to prevent damage to the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flue gas temperature exceeded
What causes this fault?
This fault occurs when the sensor detects that the gases produced by the burner have reached dangerously high temperatures. The most common reason is a buildup of scale or debris inside the heat exchanger which prevents heat from being transferred to the water effectively, or it could be due to a lack of proper water circulation. To prevent the internal components from melting or warping, the boiler shuts down as a critical safety precaution.
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 for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like E03 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Remeha Avanta Plus is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
Affiliate links — we may earn a commission at no extra cost to you.