Hello everyone. If you have an answer or even a suggestion, to my problem please let me know. I have been going crazy trying to figure this out.

I am replacing a bad Honeywell (T8411r) thermostat. The LED lights went out and I could no longer see to adjust the temp. The HVAC unit worked perfectly when I removed the thermostat.

I went to Home Depot and bought the closest thing I could find to the old T8411r... a Honeywell model RTH3100C (it has the identical switch layout). I had no idea at the time what a pain this was going to be to swap out.

The original wiring on the T8411r was as follows:

'Yellow' - Y (and jumped to W1)
'White' - W2
'Green' - G
'Orange' - O
'Red' - R
'Blue' - C
(There are two unused and covered wires... Brown and Black)

The instructions for the new RTH3100C state that I should attach the wiring as follows:

'Yellow' - Y
'White' - AUX
'Green' - G
'Orange' - O
'Red' - R
'Blue' - C

I did this and installed the batteries/faceplate. The 'cool on' message comes on and slowly flashes for about 5 minutes as it is suppose to, but then nothing happens. There is absolutely nothing... no fan, no AC, and no heat. I tried all switch settings and could not get the unit to turn at all. I also tried to switch the AUX (White) and Y (Yellow) wire but to no avail.

If anyone has any suggestions as to what I could try, it would be greatly appreciated. I am at a loss for what to try next.
Thanks !
Gary
Frustrated in Saint Pete -

Its possible you could have blown the transformer when installing,, did you check with meter to see if you had 24 volts at the red tstat wire?can be checked at the tstat, or at the furnace also double check the breakers to the furnace,, stranger things have happened

Thanks for your reply... Yes, I am possitive that the transformer is okay. I painstakingly took the time to re-install the orig T-Stat to make sure that the system was still okay. The unit came on so I know all is well with the system.

I'm not fimiliar with this t-stat but from what you've said to me looks like you need to put that jumper back to Y-W1 and make the white wire W2

Sorry that's not right

I don't believe you have a 2 stage heating t-stat wich is what the original is

I am not exactly sure what 'two-stage' means, but do you have any idea as to how I can change the wiring and get this thing up and running? Thanks.

In the old thermostat wiring

REMOVE JUMPER, WHEN SUPPLIED, FOR SYSTEMS WITH Separate HEATING COMPRESSOR CONTACTOR (W1 SEPARATE FROM Y).

Old thermostat link

http://customer.honeywell.com/techlit/pdf/69-0000s/69-1037.pdf

New thermostat link Note look at page 12

http://customer.honeywell.com/techlit/pdf/PackedLit/69-1889EF.pdf

I believe you have a wire or two crossed.

I have supplied you with the manuals for both thermostats. You should now have enough information so that you can wire it up correctly. I am sure you marked which wire came from where on the old thermostat just like it says to do in the manual for the new thermostat. If not then you will have to trace the wires back whence they came and see what part of the unit they operate.

Thank you very much (HVAC1000) for the valuable information. I will be working to resolve this problem all weekend (if need be) and will report back with the results.

I am replacing a energy star LUXPRO thermostat with a Honeywell RTH3100C Thermostat. My heating unit comes on and blows cold air for about five minutes and shut off. I jumpered the E and Aux , yellow, green and red are connected properly. The white wire is also connected te aux. Can some one please let me know if I wired the thermostat incorrectly. My 50th bithday is on New Years Day and Friends and family are scheduled to spend time with me. Thanks