Technical description
Pump operating mode, 2 stage pump: 0=Burner mode stage 2, pump flow/overrun stage 1; 1=Heating mode and pump flow/overrun stage 1, hot water handling mode stage 2; 2=Automatic heating mode, pump flow/overrun stage 1, hot water handling mode stage 2; 3=Stage 2
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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