[rfields109]

I have a 20 year old honeywell dial thermostat with 4 wires, Red Green White and Yellow connected.

I purchased a Honeywell T8001F programmable and connected the RED wire to the R connection, White to W, Yellow to Y and Green to G.

There are other wire terminals like B and O .

Once connected the unit is dead, no display and acts as if there is no power. I have voltage coming in ut am wondering if it's enough to drive the unit. This particular unit does not use batteries.


A schematic would be excellent! Honeywells installtion instructions and diagnostics are horrible and I'm hoping you folks can help.

Have a great day all.

[dac122]

Lets first get power to the unit.

Sounds like your Red is 24VAC hot and connected properly to the R terminal. You now need to connect your 24VAC common wire to the C terminal to properly power the tstat. Do you have another wire than the Red Green White Yellow mentioned above?

[rfields109]

There is a blue wire that is not connected to anything and it doesn't appear to be used. Looks like a spare.

[dac122]

Could be your missing common.

I hesitate to tell folks to just hook it up, so best is to follow that back to wherever and verify it is your common or hook a multimeter to it and Red to verify 24VAC.

[hvac1000]

You are missing the C common wire


From your Honeywell manual.

The T8001F, T8024F Thermostat is powered directly
from the system transformer. Batteries are not required
because setpoints are held permanently by non-volatile
memory.

Your manual

http://customer.honeywell.com/techli...it/69-1465.pdf


Honeywells manuals are some of the best in the industry but you need to read them carefully. The wiring diagrams are also great.

[rfields109]

The PDF link is awesome, Much more detailed than what came in the box. I needed that schematic and now I can get this thing working... Thank You ALL.

[KISS]

Hvac1000:

Honeywell manuals need improvement. I've even complained. Not a blip back.

Here is a perfect example from the VisonPro Install guide

0350 Heat pump compressor lockout
0 No heat pump compressor lockout
[Other options: outdoor sensor below 15, 20, 25, 30, 35, 40°F (-9.5°C to 7°C)]

0360 Heat pump auxiliary lockout
0 No heat pump auxiliary lockout
[Other options: outdoor sensor below 40, 45, 50, 55, 60°F (4.5°C to 15.5°C)]

The word outdoor sensor below is missing.

Documentation is a PAIN to write.

[hvac1000]

Glad it worked out for you.