F.84 displayed, inconsistent flow temperature readings, boiler may lock out

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

Loose flow NTC connector, Damaged sensor cable, Sensor intermittently open/short, PCB input fault

Safety: Turn off power before handling wiring.

Steps:

Inspect the flow NTC connector at the sensor and PCB; reseat firmly.
Check the cable for cuts or kinks; repair or replace if damaged.
Measure sensor resistance while gently flexing the cable; if readings jump, replace the sensor.

If the sensor and wiring are sound, the PCB may need replacement by a technician.

Medium 3/5

Flow NTC Temperature Sensor

Check Price on Amazon

We may earn a commission from links on this page.