Boiler displays A16, burner output limited, system may be noisy

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Faulty flow sensor or paddle switch, Blocked strainers or filters, Air lock in system, Pump not running at commanded speed

Safety: Allow system to cool before venting air or opening filters.

Check system pressure: Ensure pressure is within the recommended range; low pressure can cause poor flow.
Bleed air: Bleed radiators and any automatic air vents to remove trapped air.
Clean strainers (competent person): If a system strainer is installed, isolate, remove the cap, and clean the mesh of debris.
Technician tasks: A professional can test and replace the flow sensor or switch and verify pump performance.

Medium 3/5

Flow Sensor / Flow Switch

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