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1. Give me model on thermostat
2.If you can attach a clear pic of thermostat wires and wires at furnace will help.
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.
It is a bit hard for me t tell at furnace wiring.This is how it should be .PLease verify:
Red from furnace to red at thermostat
Green from furnace to Green at thermostat
White from furnace to white at thermostat
Blue from furnace to red outside and
Blue from thermostat straight to white outside
My first suspicion is the board,but you have changed that I understand.
Lets do this. Remove the wires from wirenuts,red,green ,white and the and red that goes outside.
Turn power on and verify nothing comes on.
Next touch RED to GREEn and see if blower ONLY comes on
Next RED to White and see if HEAT ONLY comes on
Next touch RED to the red going outside and make sure just outdoor unit comes on.
OK now wires were all disconnected right? If so thermostat should not be controlling anything.That is what we were doing was eliminating thermostat or wiring outside of furnace.
And are you saying when you connected red and green from furnace blower did not come on and when you connected red and whie from furnace heat did not come on?
OK issue has to be with board or how it is wired.Can you upload me a clear pic showing board and wires?
Thermostat is definitely not the issue as we bypassed it and everything worked. Something in that board has to be sending signal to the induced draft motor and gas valve on call for cool.I am sure you do not want to hear that it is the board since you have changed board and still have same problem.
So let me open this to other experts who may have other ideas.I will opt out to see if anyone else has ideas. Please hold rating until we see if we can get you an answer.Thanks for letting me work with you to this point.
Lets do a few slightly different tests.
Follow the wire that leaves the W terminal on the thermostat and connects inside the furnace... disconnect it and put tape on the end so that it does not short out on anything. Then turn the thermostat on so that system goes into cooling mode.
If it goes into cooling mode, without the furnace burners coming on as before, then the the problem is in the wiring between the furnace and the thermostat...
Since you replaced the thermostat, I suspect a staple used to secure the thermostat wire to the wall studs during construction has cut through the insulation and has shorted the white wire to the green or yellow wire.
Do that test, let me know how it goes.
Let me know if there are any spare thermostat wires that you can see in the thermostat wire bundle.
We can go from there.
Thermostat cable comes in 4, 5, 6 and 8 strand, If your system uses only 5 strand for instance, the installer would have pulled 6 or 8 strand cable and left the remaining wires wrapped around the end of each end of the cable.
One of those can be used as a spare to replace the white wire...in that case you will not have to pull new wire.
I can coach you how do it the easiest way to pull new wire if you have an attic. (drill through the wall plate just above the thermostat in the attic, poke the new thermostat wire through the hole and down into the wall until it hits the fire break) then remove the thermostat and use a coat hanger wire to fish the new cable through to the thermostat)
Before we do that however, do the test, remove the white wire and tell me if the heat comes on when you set the thermostat for cooling.
Hello again, you can try that, but it is about 80% likely that the thermostat wire was installed before the sheet rock, and is stapled to the studs.... another issue is that the fire break that goes between the studs is generally about 4 feet off the floor, and will have a hard time most likely pulling anything through it.
but it would not hurt to try, we might get lucky. If that fails you will have to pull it down from the attic.
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