Hi,

I called Honeywell to find out which thermostat I need for my heatpump system. I told them the current wiring on the old thermostat and was advised to buy the RTH7500 or RTH7400.

Here is how I was told to wire it:

Old to New
Y1 to Y
R to R
G to G
O to O
W1 to Aux (jumper from Aux to E)
C to C

Node setting 0170 set for #7
Node setting 0190 set for #0

However, when I was reading the instruction manual, it says if my old thermostat has Y1 or W1 (I have both) then I need to stop now and call a contractor for help. So I am confused because they didn't tell me this on the phone, they told me how to do it myself. I tried to call them back and ask why, but they are closed for the weekend.

Does anyone know why I need a contractor because of the Y1 and W1 wires?

Thanks!
Mona

carpathia wrote:

Hi,

I called Honeywell to find out which thermostat I need for my heatpump
system. I told them the current wiring on the old thermostat and was
advised to buy the RTH7500 or RTH7400.

Here is how I was told to wire it:

Old to New
Y1 to Y
R to R
G to G
O to O
W1 to Aux (jumper from Aux to E)
C to C

Node setting 0170 set for #7
Node setting 0190 set for #0

However, when I was reading the instruction manual, it says if my old
thermostat has Y1 or W1 (I have both) then I need to stop now and call
a contractor for help. So I am confused because they didn't tell me
this on the phone, they told me how to do it myself. I tried to call
them back and ask why, but they are closed for the weekend.

Does anyone know why I need a contractor because of the Y1 and W1
wires?

Thanks!
Mona




Hi,
Is the heat pump multi stage one? Also has auxilliary heat?
Better make real sure of wiring. Or it can damage the system.
Make sure first, what kind of system you have and start from there.
Then look at the corresponding wiring diagram carefully.

carpathia wrote:

Hi,

I called Honeywell to find out which thermostat I need for my heatpump
system. I told them the current wiring on the old thermostat and was
advised to buy the RTH7500 or RTH7400.

Here is how I was told to wire it:

Old to New
Y1 to Y
R to R
G to G
O to O
W1 to Aux (jumper from Aux to E)
C to C

Node setting 0170 set for #7
Node setting 0190 set for #0

However, when I was reading the instruction manual, it says if my old
thermostat has Y1 or W1 (I have both) then I need to stop now and call
a contractor for help. So I am confused because they didn't tell me
this on the phone, they told me how to do it myself. I tried to call
them back and ask why, but they are closed for the weekend.

Does anyone know why I need a contractor because of the Y1 and W1
wires?

Thanks!
Mona




Hi,
www.hvacmechanic.com forum may be better place to ask around.
Does you system have aux. heat? Is it multi-stage heat &/or cooling?

Hi, It is a multistage heat pump with auxillary heat.

Mona