703 High
Your boiler has detected a communication problem between its main internal control board and the display interface.
Technical description: E-Combi EvoE-System EVOClas HE evo combiClas he evo system
Typical repair cost: £120-£350 (including labour)
DIY fix possible
Turn the boiler power off at the fused spur switchWait for 60 secondsTurn the power back on and press the Reset button
Protect yourself from future repair bills
A boiler cover plan would cover faults like 703 — no call-out fees, no surprises.
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Parts commonly replaced
- Main PCB
- Display Interface Board
- Wiring Harness
*Affiliate links — we may earn a commission at no extra cost to you.