I bought the 'T8011R1006' programmable Digital Thermostat to replace my existing 'T874R1822', Analog Thermostat that controls a 2-Stage Heating and 1-Stage Cooling Electric Heatpump, The Sub-base model of the existing thermostat is 'Q674L1710'. The volts going into the thermostat is 24V. The thermostat also controls central Air Conditioning. The available terminals on the old analog thermostat are W2, W3, L, O, X, R, Y, E, G and B. There are 7 wires going into the W2, L, O, X, R, Y and G terminals and there is also a cross connection between the W2 and E terminals. In the new Digital thermostat 'T8011R1006' the available terminals are: W1, W2, L, O, C, R, Y, E, G and B. My doubts in the wiring are:

(1) Since there is no X terminal in the digital thermostat I bought, can I make the same connection to the C terminal?
(2) The connection to the W2 terminals from the analog thermostat should go into the W2 terminal in the digital thermostat as well, isn't it?
(3) Should I make the cross connection between W2 and E in the digital thermostat as well?
(4) All the other connections from the analog thermostat would be mapped one-on-one in the digital thermostat as well, isn't it?

Usually there is a 24 volt AC transformer in the furnace with the secondary winding connected to a red wire running to the thermostat and a blue wire to the gas valve, A/C relay, and fan relay. From the thermostat there will be white wire to the gas valve, yellow to the A/C, and green to the fan. The thermostat is wired to switch the power from the red to the white, yellow, and green as needed with the blue completing the circuit. It may be wired to have the control wires return to the furnace and its controls and then a second wire goes to the A/C unit. Internal wiring may replace the green wire if the thermostat does not give you the option of fan only or continuous fan.

The W1, 2, 3 likely are for 2 stage heating replacing the W in simpler thermostats. C may be a hot common often labeled RC and jumpered to the R. The L, O, X, and E may be connect to an outside temperature sensor, logic on the furnace control board, or externals such as a electronic filter. If you didn't get any instructions with the thermostat, you have to check Honeywell's web site or call their tech service.

Please help me, I have ten years electronics experience and I can't figure this out. I have two wires, one red, one white. Logic would dictate that since there are only two, and this is a relay type system, then it doesn't matter which way they are connected. So I have the red going to the R(Rc Jumpered) and the White going to the W. This is what is in the instructions, this is what I did. Only the boiler never kicks on. I shorted the wired together and the boiler works fine. I tried playing with the Thermo and a meter. None of the connections ever short together whether the system in on or not. Am I doing something wrong or is my thermo shot?

I think RC powers the thermostat off the red wire, and the thermostat switches the R to W, G, or Y as needed. Maybe backwards for the R and RC. Don't understand how the thermostat power connects to the other terminal of the transformer unless it bleeds enough power back the white wire all the time to power the thermostat, but not activate the gas valve.

If shorting the red to white fires the boiler, and connecting them to R and W doesn't with it is heat mode, I don't think it is working.

I have the same question. Did anyone ever figure it out?
I have a brown "X" connection on my old system, and it doesn't seem to map to anything on my honeywell unit.

What would a brown wire going to X be?

On the old unit there's 7 wires:
Green
Red
Blue
Yellow
Brown - X
White - w2
White(looks like its just jumped from e to w2).


The new unit is 'universal'
It has the following hookups but not all need to be used:
Y2
L
E
AUX/W2
S1
S2
RC
R
W / O/B
Y
G
C


So I know that my current:
G, R, B, Y, and W2 map directly over.
For e should I jump it from W2, or just not hook it up?
And X I have no clue at all. It looks like it either goes to C, RC, S1, S2, L, or Y2