Sime Air Pressure Switch 0.6 mBar 6225702

This is an air pressure switch rated at 0.6 mBar, supplied as Sime part number 6225702 and built to the Honeywell C6065F1050 reference. It monitors the pressure produced by the combustion fan and proves airflow before the boiler is allowed to fire, so it sits directly in the ignition safety chain. The switch is used across the Sime Friendly and Sime Super appliance families.

• The fan runs but the burner does not light and the boiler goes to lockout.
• Ignition is intermittent, with the boiler firing on some attempts and locking out on others.
• The boiler locks out shortly after start-up and resets only briefly before failing again.
• Fault codes or lockout patterns that point to an air pressure or fan proving fault.
• Visible damage, contamination or a blocked sensing tube at the switch.

• Check the GC number on the appliance data badge against the compatibility list before ordering, as the same boiler name can cover more than one build.
• Confirm the part number on the existing switch matches 6225702, or that the fitted item carries one of the alternative numbers listed here.
• Inspect the sensing tube and its connections at the same time; a split or blocked tube can produce the same symptoms as a failed switch.