Sorry, long post but I want to get every detail in here.
I believe the furnace in my new to me home is not wired correctly. I was wondering if someone can verify what I think I have here. I am comfortable with the wiring part, I am just not that familiar with HVAC systems.
I have a Ruud 90 Plus NG furnace with "Dual Comfort Control" which I believe means that it has two heat stages. I also have an air conditioner. Both installed around 2009/10. They are controlled by a basic programmable thermostat. I have been using the furnace for the past week or so since we moved with no issues. Have not used the A/C.
Today, I went to switch the fan from Auto to On but nothing happend. First thing I did was pull the cover of the t-stat to see how it was connected. I found that I have a 6 wire cable there but only 3 wires are connected to the t-stat.
I have RH/RC (Black with Red jumper), W (White) and Y (Blue) connected. So 24V+, Heat Call and Cool Call from what I gather.
At the furnace end the 6 wire cable comes to about 2 feet from the unit and the 3 connected wires from the t-stat are spliced to a 5 wire cable that goes into the furnace. Blue is spliced to green here, otherwise black and white are the same. The remaining 2 wires in that cable are not connected. Why, I don't know. My guess is that the 6 wire cable was too short when the unit was installed so they extended it with a 5 wire cable they had on hand.
In the furnace, I have R, C, W, W2, G and Y/Y1 terminals. The RC/RH wire from the t-stat (Black) is connected to R, W to W and Y (Now Green) to Y/Y1. The A/C unit is connected to C (Black) and Y/Y1 (White) at the furnace.
So for whatever reason the G terminal was never connected to the t-stat for fan control. Why, I don't know. Ideas? That is a straight forward fix. I will just use one of my spare wires and connect G to G to get fan control. No problem there, right?
Now, what I'm unsure about is the two stage heat. I don't know anything about this function of the unit. I assume because the W2 terminal is not connected that it will not function. I don't think my t-stat is multi-stage compatible because it has no W2 terminal. This probably explains why it was not connected in the first place. But why would someone buy a furnace with this feature and not want to use it?
If I get a new compatible t-stat, is it as simple as just connecting W2 in the furnace to W2 on the t-stat to get the multi-stage heat functioning? Is it that simple or is there some kind of programming that would need to be done on the furnace end? From reading, I think there is a jumper that may need to be moved from single to dual stage. I will have to verify when I get back in the furnace, but is that it? Will the t-stat and furnace control board do the rest?
So, thoughts? I would like to get the fan and two stage heat working but I don't want to mess anything up in the process. Am I missing something here that could be a problem when I connect everything the way that I am explaining here? Again, its not the wiring that I am concerned about, more the function of the furnace.
Thanks,
Jaime
I believe the furnace in my new to me home is not wired correctly. I was wondering if someone can verify what I think I have here. I am comfortable with the wiring part, I am just not that familiar with HVAC systems.
I have a Ruud 90 Plus NG furnace with "Dual Comfort Control" which I believe means that it has two heat stages. I also have an air conditioner. Both installed around 2009/10. They are controlled by a basic programmable thermostat. I have been using the furnace for the past week or so since we moved with no issues. Have not used the A/C.
Today, I went to switch the fan from Auto to On but nothing happend. First thing I did was pull the cover of the t-stat to see how it was connected. I found that I have a 6 wire cable there but only 3 wires are connected to the t-stat.
I have RH/RC (Black with Red jumper), W (White) and Y (Blue) connected. So 24V+, Heat Call and Cool Call from what I gather.
At the furnace end the 6 wire cable comes to about 2 feet from the unit and the 3 connected wires from the t-stat are spliced to a 5 wire cable that goes into the furnace. Blue is spliced to green here, otherwise black and white are the same. The remaining 2 wires in that cable are not connected. Why, I don't know. My guess is that the 6 wire cable was too short when the unit was installed so they extended it with a 5 wire cable they had on hand.
In the furnace, I have R, C, W, W2, G and Y/Y1 terminals. The RC/RH wire from the t-stat (Black) is connected to R, W to W and Y (Now Green) to Y/Y1. The A/C unit is connected to C (Black) and Y/Y1 (White) at the furnace.
So for whatever reason the G terminal was never connected to the t-stat for fan control. Why, I don't know. Ideas? That is a straight forward fix. I will just use one of my spare wires and connect G to G to get fan control. No problem there, right?
Now, what I'm unsure about is the two stage heat. I don't know anything about this function of the unit. I assume because the W2 terminal is not connected that it will not function. I don't think my t-stat is multi-stage compatible because it has no W2 terminal. This probably explains why it was not connected in the first place. But why would someone buy a furnace with this feature and not want to use it?
If I get a new compatible t-stat, is it as simple as just connecting W2 in the furnace to W2 on the t-stat to get the multi-stage heat functioning? Is it that simple or is there some kind of programming that would need to be done on the furnace end? From reading, I think there is a jumper that may need to be moved from single to dual stage. I will have to verify when I get back in the furnace, but is that it? Will the t-stat and furnace control board do the rest?
So, thoughts? I would like to get the fan and two stage heat working but I don't want to mess anything up in the process. Am I missing something here that could be a problem when I connect everything the way that I am explaining here? Again, its not the wiring that I am concerned about, more the function of the furnace.
Thanks,
Jaime
