F.762 System pressure too low

What the control is telling you

System in a fault state.

Applies to: Vitodens 200-W B2HE 85, 120, 150, 199

Likely causes

• Low water pressure
• Expansion tank
• Safety chain plug

Test and repair steps

1. Top up with water and vent the system.
2. If repeated, check the minimum pressure switch with an external gauge.
3. Check expansion tank pre-charge.
4. Check safety chain plugs on the BCU.

Models that show this code

4 models in Vitodens 200-W B2HE

Other codes on the same units

• F.71 Fan speed too low
• F.72 Fan idle state not reached
• F.73 BCU internal communication error
• F.74 Water pressure too low, burner locked out
• F.763 Gas pressure too high
• F.764 Lag boiler reports a fault
• F.765 Lead boiler communication error
• F.77 BCU data memory error