Is Thermostat Breaking down?

[artrosch]

I got a rebuilt four button duotherm thermostat a couple years ago and it's served us well. Today I came to turn on the air conditioning and nothing happened. I noticed there was no zone indicated. Our is a two zone system. I tried to do the reset procedure but nothing changed. I'm stumped. Is the 'stat going out? It's been a little stubborn, requiring multiple hits on buttons, but it's always done that. The light goes on, temp changes, mode changes, fan changes. There's just no zone, and nothing happens with the duotherms. They don't go on in any mode.

Thanks

Art

[RedRocket]

You check your fuses?

[Tha_Rooster]

I had one that the circuit board would corrode on the back and it would go completely out I could clean and replace back on wall good as new.

["007"]

Art, Go to page # 18 of PDF and try a reset of your control see if that helps.
You could also have a defective control board in your first AC housing where the control feeds to as you can see on next page of PDF.

[scenic route]

"007", what a great link...I have this system as well and it is now logged into my 'favorites' file for perusing later. Thank you Bob

[artrosch]

I plugged/unplugged the RJ11 at the t'stat quite a few times, cleaned the contacts and it's working again. I replaced the circuit board in unit#1 a couple weeks after I replaced the t'stat, so I've picked up some familiarity with the system. That's a great link, 007. Muchas gracias!