Honeywell T882 Chronotherm Clock Thermostat needs replacement

It must be wired or it will not work.
Take a look at the installation instructions before you attempt any reconfiguration!

R= power in G= fan Y= cooling W=heat O= heatpump reversing valve C= common used for clock on chronotherm Usually its pretty streight forward wire for wire. Unless you have a heatpump. The thermostat has to be heatpump compatable. And I ll usually use the 8000 for this. The w and y jumper may not be necesary on the new thermostat as the new one should do it internally once programed as a heatpump thremostat. At least thats how the 5000 and 8000 sreies work. So imagine the 7000 would be the same. You may also have to program the reversing valve operation not all manufactuers do it the same . Some valves have to be powered for heat while others have to be powered for cooling. Good luck

Chronotherm was a Honeywell thermostat from the 70s-80s. Better off going to home depot and replacing it. Wiring is not that hard, they give you labels for the wires. It is low voltage and will not sting you, but turn off heating unit first to avoid shorting out transformer.

No. The clock is just the set back timer. Pull the battery and use the stat manually.

Unfortunately, no. These clocks fail frequently.

It would appear to me that you have lost the 24 volt power supply to the thermostat. In referencing the manuals for this thermostat, available @ www.honeywell.com, I've found that when the thermostat is not connected to the wall plate (plate mounted on the wall, that the thermostat either snaps or screws into), it will display the -AC. This being said, either the thermostat is loose on the wall currently, or your 24 volt transformer has died. Hope this helps.

Hi,
Yes, you should be fine by just connecting to the R and W terminals. The wire to the R should be the one coming from the R on the furnace or air handler.
Make sure that you nut off the other two wires good so that you don't short out the transformer.
It is a good idea to disconnect power before moving any of the wires to make sure you don't accidentally short them out.

I hope that this will help you to solve your problem!

Thanks for using Fixya!!

Heatman101

Open the air handler. Locate the low voltage transformer. One side is 220 volts input. The other is 24 volts output. Take your VOM and touch the test leads to the input to verify 220v in. Then touch the other 2 leads to verify 24v out.
If you have power in and no power out, replace the lv transformer.

Hi, your replacement part can be purchased on amazon, take a look here: Amazon com honeywell chronotherm III thermostat. I hope this was helpful. Cheers

Check to see if you have wires going to a C/C1 terminal. The older chronotherms used a transformer to supply 24 volts to power the clock. If in fact you do have these terminals, then I would suggest checking the output voltage on the transformer, (secondary (24v)side) to ensure it isn't close to dead. Hope this helps