How much does it cost to fix Ideal error code 93 H.....4....?

Typical repair cost for the Ideal 93 H.....4.... fault is £120-£280 including labour.

93 H.....4.... High

Ideal 93 H.....4.... Fault Code

Q: What does the Ideal 93 H.....4.... fault code mean?

Your boiler has detected that it is firing without enough water inside, which has caused the temperature sensors to overheat or report a fault.

Also written as 93H4 — same fault.

The Ideal 93 H.....4.... fault code means: your boiler has detected that it is firing without enough water inside, which has caused the temperature sensors to overheat or report a fault.. It appears on 3 Ideal models in our database.

Technical description: DRY FIRE THERMISTOR ERROR

What causes the Ideal 93 H.....4.... fault?

This fault occurs when the boiler fires up but detects an immediate, rapid rise in heat because there isn't enough water circulating to carry that heat away. The most common reasons are a severely trapped pocket of air, a seized pump, or a major blockage in the pipework that is preventing water from reaching the heat exchanger.

This issue is more frequent in autumn when heating systems are switched back on after a long summer break, as pump components can seize up during periods of inactivity.

Typical repair cost £120-£280 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Ideal models that show the 93 H.....4.... fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Ideal 93 H.....4.... fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026