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Honeywell thermostat T8400c started flashing, heat/cool was off. Display flashes all icons (heat and cooling icons, temperatures, everything) and on the oppposite flash, the setpoint is displayed. The fan comes on when turned to ''ON'' but heat or cool does not when in ''auto''. The compressor can be turned on outside at the switch, but appears to have no freon. Heating & cooling worked within 2 weeks prior to this issue. Any help would be greatly appreciated.

Answers :

Based on the simplicity of this particular t-stat, I really think that it is bad and needs to be replaced. They do not make this particular model anymore. I have included a link to the operators manual for the stat. Good luck!

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Honeywell thermostat T8400c started flashing, heat/cool was off. Display flashes all icons (heat and cooling icons, temperatures, everything) and on the oppposite flash, the setpoint is displayed. The fan comes on when turned to ''ON'' but heat or cool does not when in ''auto''. The compressor can be turned on outside at the switch, but appears to have no freon. Heating & cooling worked within 2 weeks prior to this issue. Any help would be greatly appreciated.

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