E43 High
Your boiler has detected an electrical fault with the internal sensor that monitors the temperature of the water returning to the unit, causing it to shut down for safety.
Technical description: Return sensor short circuit – check connections to return sensor
Typical repair cost: £90-180 (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 E43 — no call-out fees, no surprises.
*Affiliate links — we may earn a commission at no extra cost to you. Prices shown are starting prices.
Parts commonly replaced
- Return thermistor (NTC sensor)
- Sensor wiring harness
*Affiliate links — we may earn a commission at no extra cost to you.