What the manual says
Manufacturer manualDecrease/increase heating circuit pressure - check for leaks on the heating circuit, faulty filling-loop, expansion vessel faulty
From this model's manual
Verified against the Ariston/Ariston Genus 30 Plus installation & service manual.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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All 10 fault codes on the Genus 30 Plus
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