How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask airheatman Your Own Question
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8164
Experience:  Furnace, A/C and heat pump specialist.
Type Your HVAC Question Here...
airheatman is online now
A new question is answered every 9 seconds

I installed a honewell smart

Customer Question

I installed a honewell smart wifi thermostat for my airease forced air single stage furnace following all the instruction i. The manual and videos. All seemed to work after installation and programming but I suddenly noticed that insted of heat, the AC was on and the fan would not stop. As I do not have a c wire in my old battery operated thermostat I followed the instruction using the G wire as C and making the appropriate changes on the furnace. I turned everything off and double checked everything . I finally took the r-rc connector out as I do have an R and rc wire connected to the repective connections. This was recommended in the manual. When I turned the system back on.....nothing. Neither heat or a/c would come on. I checked the orange fuse on the pannel and I looks fine. In the end I reinstalled my old thermostat but nothing works either. I am stumped. Can you help?
Submitted: 2 years ago.
Category: HVAC
Expert:  airheatman replied 2 years ago.
Hello. My name is ***** ***** I'll do my best to help. Let's get started and see what we can do.What is the complete model on the new thermostat? (EX RTH8550SF)
Customer: replied 2 years ago.
Expert:  airheatman replied 2 years ago.
OK lets do this. Verify where each wire is coming from in the furnace to thermostat and where each wire is coming from in the outdoor unit. It is going to be important that the R we connect to R terminal is coming from the same transformer (furnace transformer)as the wire going to C and the wire to Rc is coming from the outdoor unit transformer in you have a 2 transformer setup.
(In otherwords if we have R from one transformer and C from a different transformer, that will not supply a complete circuit to thermostat.
Customer: replied 2 years ago.
How do I find out where the wire is coming in from the outdoor unit?
Expert:  airheatman replied 2 years ago.
Do you have a multi meter? If so. turn power off to units. Then in outdoor unit disconnect the wires and twist them together.Then at thermostat, check to see which wires show continuity between them.
Customer: replied 2 years ago.
I cannot do that. I am not a professional and don't want to do any damage!
Expert:  airheatman replied 2 years ago.
I understand. Lets do this.At thermostat.take both reds and green wire loose. Touch each red to the green and see which one makes the indoor fan come on. That red will be the one from furnace and needs to go to R.The other red will be from outdoor unit.
Customer: replied 2 years ago.
The red wire in RC
Expert:  airheatman replied 2 years ago.
You stated earlier that you have 2 red correct?
Customer: replied 2 years ago.
I have a blue wire in R and a red wire in RC
Expert:  airheatman replied 2 years ago.
Does the blue wire connect to R in furnace?. Can you upload a picture at thermostat, furnace and outdoor unit control wiring?If you have a paper clip icon on your page you can attach using that link.Or
You can upload the pictures using the tiny pic site .
Here is a link to the site.
Click on Browse , select the file from your folder.then click UPLOAD NOW.
They will give you a quote to enter in the box to verify you are a human.Enter the quote and click UPLOAD NOW
You will see your picture on right side of screen.
Then copy the link URL for email & IM
Paste that link here on the site.
Customer: replied 2 years ago.
No the red does but I just found out that the blue wire from the thermostat connects to nothing in the furnace. The blue wire in the furnace is in C and connects to a humidifier, not connected to the thermostat. In the old thermostat there is a terminal connector between R and RC. There is also one in the new thermostat.
My present problem is that I reinstallled the old thermostat the way it was and nothing works. i am sending pictures.
Expert:  airheatman replied 2 years ago.
Pictures will help. These days it is unusual to have a second transformer most system just use one in furnace.
Wiring is usually as follows. Furnace wires : Red to R with jumper to RC,White to W, Green to G and whatever color from C in furnace to C at thermostat. Then only 2 wires from outdoor.One to Y at thermostat and the other to the C terminal in furnace.
Now since you are using your G as the C wire, You would have as follows:
Red from furnace to R with jumper to Rc,White from furnace to W, C at furnace to C .THen from outdoor, one wire to Y at thermostat and the other wire from outdoors to C at furnace. You also need to put a jumper in furnace from Y to G so blower will be energized on call for AC.
Let me know how many wires you actualy have coming from outdoor unit will also help.
Customer: replied 2 years ago. accepted one photo and is not responding any longer the link is
Expert:  airheatman replied 2 years ago.
1. Do all of those wires go to thermostat?
2. Do you have another set of wires going to outdoor unit?
Customer: replied 2 years ago.
I have no idea of what wires go to the outdoor unit. I see 6 wires coming in to the furnace. Red goes to R Blue from the humidifier goes to C.
White to W, yellow to Y and green to G.
On my old honeywell thermostat, green goes to G , Yellow goes to white
And red goes to R that has a jumper with Rc.
It used to work but now it does not work.
Expert:  airheatman replied 2 years ago.
For me to help. I have to know what wires are going to outdoor unit, what wires are going to furnace and what wires are going to thermostat.If you cannot provide this info, it is probably going to require calling in an onsite tech to see what you have. I can request a refund of your deposit or open the question to other experts to see if they can help.
Just let me know what you want to do.
Customer: replied 2 years ago.
Thank you but I would like a refund and will call someone to come and help.
Expert:  airheatman replied 2 years ago.
I understand. Will forward request to administrators.

Related HVAC Questions