Hello,

I had an OLD honeywell (circa 1983) and labeled the wires that were attached to it as follows:

blue -> b
white -> w2
brown -> x
green -> g
yellow -> y
red -> r

I was able to get cooling to work. And now, with heat on, it blows air, but it isn't hot air. I've tried the settings 2 and 7 on option 170. Currently, I've got it wired:

b -> o/b
w2 -> aux
x -> c
g -> g
y -> y
r -> r

I've even taken the 'hood' off to check wires inside. It turns out my b wire is connected to an orange wire. I was unable to trace it further so it may be that that orange wire is actually connected to where a blue one is supposed to be.

Anyway, I sure would appreciate any help.

 

Post the Q674? - ???? number on the old stat if you still have it.

Set option 170 to 7 and 190 to 1.

 

Thank you for the response and WOW, what a good guess.

I would not have been able to find it without that. The old one was a T874 with one setpoint lever. If you go here:
https://customer.honeywell.com/resou...0s/60-2485.pdf
to the bottom of page 6. Our old one was the one on the left.

I've tried the new thermostat on 170 7 with 190 1 and it it's still just pushing room temperature air.

I was also finally get back home and get a picture of the wiring in case that will help.

 

The T87 rectangular stats were matched with a variety of subbases.
If you post the Q674 number on the subbase along with all terminals on it (even the unused terminals) I may be able to look it up.



It looks like Orange and Black were in use with the old stat.
Were they?

 

Orange and Black were not used.

I had a blue cable attached to B terminal.

I also had a brown cable that was attached to an X terminal.

It looks like it was a Q674F as it is the only one that has an X terminal. I also remember that it didn't have a W1 terminal, which I thought odd.
I found this table in the T874 manual. I've *'d the connections I had
Table 5. Terminal Designations
Standard Terminal Designation | Alternate Designations | Typical Connection
* B | | Heating damper motor; changeover valve
E | K | Emergency heat relay
* G | F | Fan relay coil
L | | System monitor
O | | R Cooling damper motor; changeover valve
* R | V | Power connection to transformer internallyconnected for heating and cooling)
RC | | Power connection to cooling transformer
RH | | Power connection to heating transformer
W1 | H1, R3 | Stage 1 heating control
* W2 | H2, Y, R4 | Stage 2 heating control
W3 | | Stage 3 heating control
Y1 | C1, M | Stage 1 cooling control
Y2 | C2 | Stage 2 cooling control
Y3 | | Stage 3 cooling control
* X | X1,X2,C | Clogged filter switch or common connection
T | A | Outdoor thermistor
| L, C, H | HSII control panel
| P | Defrost
| O | Momentary circuit, changeover
| A, A1, A2, Z, C, L | LEDs
| T | External temperature readout, T relay
| R1, R2 | LO and HI speed fan relays
| RS | Cooling contactor
* Y | M | Compressor contactor

 

Is that a picture of your actual subbase or one that you found on the internet?
There are many subbases with X.
Some swap the purpose of X and B.

It helps to identify a subbase when you list the unused terminals like K and H and T.

These are some without a W1 terminal.
Looks like the Q674F had 3 LED's, did yours ?

 

We got rid of the base a few months ago, when I thought I had it wired correctly.

I don't remember how many LEDs it had. I know that none of them worked if it had any at all.

I guess I'm going to have to pull the unit apart and trace each wire.

Hopefully that will help.

 

Here are the wiring diagrams for the unit. Maybe that will help.

I also traced the wires from the wall (old thermostat terminal) -> to the wire color in the unit

Brown (X) -> Brown -> to the inside
Green (G) -> Green -> to the inside
Yellow (Y) -> Yellow -> to the outside
Blue (B) -> Orange -> to the outside
Red (R) -> Red -> to the inside
White (W2) -> White/Black -> to the inside
Orange -> Nothing
Black -> Nothing

 

Your wiring looks good to me.
With 170 at 7 and 190 at 1, give it a heat demand then feel the large, insulated copper pipe to the unit. Is it hot or cold?