I have a Honeywell RTH6580WF Wi-Fi Thermostat that has "Cool On" or "Heat On" flashing in an endless loop. Could there be a major issue?

wire it the same way!

Press Fan & up arrow @ the same time until you get into programming mode. download the manual & go through the numbered steps until you get to the turn wifi on & off. When you turn it on, it should show up on your computer wifi list. then program the wifi the same way you did initially with the other router.

You might want to check if the wires are ******* in tight on the stat and make sure the wiring matches the furnace or air handler connection Example r to r. W to w,g to g,c to c ,y to y, and there should be a jumper wire between rh and rc

Trouble Shooting - - FAQs ' FWD - Honeywell

lyric.honeywell.com/support/troubleshooting/

How do I delete that thermostat from my Lyric app? If you've moved and ... How do I change the email address I use to manage my Lyric? If you already have a ...Missing: programmable ‎accurate

Wi-Fi 7-Day Programmable Thermostat ' Honeywell

yourhome.honeywell.com/.../thermostat/wi-fi-7-day-program...

HoneywellThe Wi-Fi 7-Day Programmable Thermostat is designed for the way you live ...Features such as Smart Response and precision temperature accuracy bring ... your home heating and cooling system, and then remove your existing thermostat. .... Whileconnecting to Wi-Fi, my model RTH6580WF or TH6320WF thermostat is ...

FAQs - Total Connect Comfort

Thermostats don't actually blow anything, the heating system might though. Check the breakers for your heat system, then call a heating specialist. They're really not that expensive.

should have a reset .

If you need further help, I’m available over the phone at https://www.6ya.com/expert/richard_b59056c0c62ecb00

Did you try E too aux and x1 to c?

Hello Dan, I found this online and thought you may be interested in taking a look at it. Here's the website address and hope it's informational. http://yourhome.honeywell.com/home/Products/Thermostats/7-Day-Programmable/RTH6580WF.htm

If this doesn't solve the problem, you might have a defective thermostat.

It is actually an extensive process to reset or reconnect with a new wifi setup. To try to explain it would probably be confusing and couldn't give you step by step. Here is the link to the installation instructions that explain it perfectly and visually, https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-2718EF.pdf
Hope this helps!

Same problem here. Gas, hot air furnace with A/C. Fan works with heat, but not A/C. Furnace is old, and I had to move the G wire to C at the furnace, plus install a jumper from Y to G.