F14 displayed, furnace will not start after power interruption or wiring changes

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

Incorrect wiring of room thermostat, Open circuit on Glow-worm eBUS or 24V control, Faulty external programmer, Short between control terminals

Safety: Isolate power before accessing wiring terminals.

Checks:

Ensure any external controls (room thermostat, programmer) have power and are calling for heat.
Check that control wiring is correctly connected to the designated Glow-worm terminals (e.g., eBUS, 24V room stat).
Temporarily link the call-for-heat terminals at the furnace to see if it starts (for technician use only).
Inspect for damaged or crushed thermostat cables.
Correct wiring errors or replace faulty external controls as needed.

Medium 3/5

Room Thermostat / Control Wiring

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