dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
1603
share rss forum feed


ropeguru
Premium
join:2001-01-25
Mechanicsville, VA

Thermostat Install Help

Have a Trane system installed and trying to install a Honeywell Thermostat.

Trane connections: TCONT401

R
O
Y
B
G
W1
W2

Honeywell Connections: RTH8580WF

R
O/B
Y
G
C
E/AUX

I am guessing the following:

R=R
O=O/B
Y=Y
B=C
G=G

But I cannot figure out w1 and w2. W1 works on set of heat strips and W2 works another. Honeywell support suggested tape off w1 and put w2 under E/AUX.

Any ideas?

»www.butcherdistributors.com/Imag···ller.pdf

»passthrough.fw-notify.net/downlo···uide.pdf


Tex
Premium
join:2012-10-20
kudos:2
If W1 and W2, separately, are the same amount (kW) of electric heat, it wouldn't matter which one you used. Depending on how many kW of electric heat you have and depending on how much heat W1 and W2 each control, you might have to experiment to see what works. In the end, you may even need to use both W1 and W2 for E/AUX.


pende_tim
Premium
join:2004-01-04
Andover, NJ
kudos:1
Reviews:
·Comcast
reply to ropeguru
I assume you have a single stage heat pump with 2 stages of supplemental heat. If you in fact have a system with 2 stages of supplemental heat and want to maintain that functionality, you have the wrong T'stat.

While you could wire only to W2, you would loose the staging functionality and possibly some comfort. With all the supplemental heat coming on at once, under moderately cold conditions, the inside temp could overshoot. This will not be comfortable and will waste energy.

Depending on the nature of the supplemental heat, there may be a setting in your furnace where the second stage can be programmed to kick in 10 minutes or so after the W1 call. In this case you only would need to wire to the W1 connection. This may help comfort and overshoot.

If it were my choice for the system I assume you have, I would install a Honeywell TH8320U1008 or TH8321U1006 which adds humidity control
--
The difference between genius and stupidity is that genius has its limits.


mackey
Premium
join:2007-08-20
kudos:12

2 edits
reply to ropeguru
Cap W2 and put W1 under the "E/Aux" terminal. The Trane manual shows it connected to an outdoor temperature switch which jumps W1 to W2 should the outside temperature drop too low.

On the old 'stat, when "Emergency" mode is selected, the compressor does not run at all, and a single heat strip is uses unless the outside temperature is too low (in which case both are used). When "Aux" is triggered ("normal" heating mode but the inside temp drops too far below the setpoint) the compressor and one set of heat strips run. Should the outside temperature be too low or the system is in defrost mode, "Aux" also turns on both sets of heat strips.

Capping W2 and using W1 under E/Aux uses 1 heat strip when "Aux" is triggered normally, and both strips when "Aux" is triggered and either the outside temperature is too low or the system is in defrost mode.

/M


ropeguru
Premium
join:2001-01-25
Mechanicsville, VA
ON my system, and I forgot to mention it, there is no outdoor thermostat that I know of. Inside the air handler there is w1, w2, and w3 in which w2 and w3 are tied together.

I saw the section you are referring to about ODT-A and ODT-B which as far as I know I don't have either one. THey refer to an external unit for the ODT and I do not have that. I will do some more research on that and see what I can come up with.


mackey
Premium
join:2007-08-20
kudos:12
The ODT is most likely built into the outside unit. If you follow the wires and both W1 and W2 go to the defrost board, then it's somewhere in there.

/M


ropeguru
Premium
join:2001-01-25
Mechanicsville, VA
Thanks... I am guessing that the ODT-A is internal to the outside unit and that ODT-B would be the external unit in a waterproof enclosure they were talking about.