E 04 High
Your boiler has lost the ability to measure the temperature of your tap water, meaning you will likely have no hot water until the sensor is fixed.
Technical description: Domestic hot water (DHW) temperature sensor failure – possible error with electronic card or the NTC sensor.
Typical repair cost: £90-210 (including labour)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Protect yourself from future repair bills
A boiler cover plan would cover faults like E 04 — no call-out fees, no surprises.
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Parts commonly replaced
- DHW NTC Temperature Sensor
- Main PCB (Electronic Card)
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