Trane natural gas heater (uplow gas fired, single stage, fan-assisted combustion system)
13 years old
+I have 2 identical systems and one does not work
Furnace does not cut on.
The diagnostic LED on the control unit blinks continuously slowly indicating no call for heat, but I have power to the thermostat and to the control system
Interior circulation fan does run when I cut on the Fan auto to fan on switch.
Any place on the internet I can find a diagnostic procedure?
Mitchell