Boiler displays E17; may indicate flow switch or flow sensor error; unit may overheat or short cycle

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

Stuck or scaled flow switch, Air in system preventing flow, Failed flow sensor, Pump not running

Safety: Turn off power and allow the system to cool. Some water spillage may occur when removing flow components.

Bleed system: Remove air from high points and radiators to ensure proper flow.
Check pump: Confirm the primary pump runs during a call for heat. If not, test and replace as needed.
Inspect flow switch/sensor: On NTI models with a mechanical flow switch, remove and check for debris or scale preventing movement. Clean or replace. For electronic flow sensors, inspect wiring and replace if readings are erratic.

Medium 3/5

System Flow Switch / Flow Sensor

Check Price on Amazon

We may earn a commission from links on this page.