Natural Gas Furnace and Central Air unit - no electricity???
#1
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Natural Gas Furnace and Central Air unit - no electricity???
The furnace is an Armstrong Ultra II 97 High Efficiency, Model# EG6E80DC16-4.
Really, this has nothing much to do w/ the air conditioner now that it's getting a wee bit chilly here in the Midwest, but it kind of does.
So a few weeks ago, we turned off our central air unit, which had worked flawlessly until today, I went to turn on the heat today and there was nothing. The blower didn't kick on nor was there any indication that the pilot light lit either. So, I turned it to Cool and way down to try and get the central air to kick on, and still nothing.
I ran to the store and got a new thermostat (hoping that was all it was, and the other one was less than a year old), but that didn't work either. I'm thinking now that there is NO power to either unit because that's the only thing that I could think would cause neither the central air or the furnace to respond to the thermostat. I checked the breakers, and they weren't tripped. I checked the fuse by the furnace switch and it's not blown.
Not sure where to go from here. Do I call an electrician or a furnace repair man?
Or anything else that I could try to troubleshoot the actual problem? It seems odd that the air conditioner responded to the thermostat a few weeks ago, and now, neither the air conditioner or furnace will respond to it now.
Really, this has nothing much to do w/ the air conditioner now that it's getting a wee bit chilly here in the Midwest, but it kind of does.
So a few weeks ago, we turned off our central air unit, which had worked flawlessly until today, I went to turn on the heat today and there was nothing. The blower didn't kick on nor was there any indication that the pilot light lit either. So, I turned it to Cool and way down to try and get the central air to kick on, and still nothing.
I ran to the store and got a new thermostat (hoping that was all it was, and the other one was less than a year old), but that didn't work either. I'm thinking now that there is NO power to either unit because that's the only thing that I could think would cause neither the central air or the furnace to respond to the thermostat. I checked the breakers, and they weren't tripped. I checked the fuse by the furnace switch and it's not blown.
Not sure where to go from here. Do I call an electrician or a furnace repair man?
Or anything else that I could try to troubleshoot the actual problem? It seems odd that the air conditioner responded to the thermostat a few weeks ago, and now, neither the air conditioner or furnace will respond to it now.
#2
You will need to verify 120V is coming into your furnace and 24V at the thermostat. Verify the cutoff switch next to the furnace is turned on. A lot of times there is a receptacle in the same switch box that you can use to power tools, lights and etc. That switch must turned on or you won't get power to the furnace or the 24V transformer required to control your thermostat and other controls for your furnace and a/c. If the switch is turned on you and you have the outlet there you can plug in a radio or other device to see if there is power there.
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The fan doesn't come on either, sorry I forgot to add that. I do have a meter to test but not sure how to do that. If you can advise me what to check and where then I can do that and get back to you.
#4
Make sure the service switch next to the furnace is on. Sometimes people turn it off not knowing what it is. You also can check to the 5A automotive type fuse on the control board. Shut the power off to the furnace before touching anything inside the furnace! I have attached a photo of am Armstrong furnace control board. Look for the amber colored rectangle with 5 on it. That is the fuse that needs to be checked to make sure it is not blown.
Last edited by firedawgsatx; 10-06-13 at 05:47 PM.
#12
That ignition control is what controls your ignitor to spark and your gas valve to open. I am really not familiar with your particular furnace. Your supply power comes into right side of your furnace where the switch is located. You will need to take your multimeter and set it to VAC. Find the black wire and white wire that enter the furnace and see where they connect. Take your red lead on the meter and place it on the terminal where the black wire is connected and place the meter's black lead on the terminal where the white wire is connected. You should have a reading of around 120V. It is hard to tell from the photos you provided but it looks like the white wire coming fom the junction box is wire-nutted to a wire going to the inducer motor. If that is the case, that connection under the wire-nut is where you would stick your black lead.
#14
Ok. I have attached one of the photos you provided with some labels on the various parts. Find the metal box on the right hand side of the photo labeled Junction Box. That is where you will need to find a black wire and a white wire that has voltage coming from the electrical panel to your cutoff switch on the side of the furnace. That is the best place to see if you have voltage coming into the furnace. Find the transformer/relay and locate the black and white wires that enter the transformer. The black wire is "hot" and the white is neutral. The black wire may be connected to a red wire coming from the limit switch in the photo. The white wire should be connected to a white wire in the junction box. First I would suggest you find the circuit breaker for the furnace and reset it or if it has fuses make sure the fuse is good. The 120V is supposed to come from interlock switch. So to do any voltage testing you will have to tape the switch down or hold it down while doing voltage tests.
Last edited by firedawgsatx; 10-07-13 at 07:10 AM.