Added details about switching AC to heat!?!?

Question

Okay, we installed a thermostat last winter & it heated the house fine. When the summer came, the AC would not blow cold air, it just blew hot air. I called my friends husband & he said the thermostat only works for heat or AC, either one at a time & that he had to "switch" it from heat to AC. After he came over & spend 5 mins. "switching" it over the AC worked perfectly but the heat wouldn't blow hot air, just cool air.. which was fine b/c it was summer time. Now we are back in the winter weather & I dont know how to "switch" from AC to heat. So my friend isn't married to the guy that came over & "fixed" it last time & Im not sure what to do!?! It is a Honeywell Non-programmable thermostat RTH5100B & I guess it only supports either heat or air, one at a time. I did notice that the guy that "fixed" it last time took the face off the thermostat. Does anyone know how I might can try to switch this from cool air to heat? Its going to be a very cold night tonight & it would be nice to be able to be warm in the morning! Thx!!
42 minutes ago - 4 days left to answer.
Additional Details
Okay, took the "face" off the thermostat & I do not see anything that says heat or AC. I do see wires & I will tell u what color they are & where they are connected.
Red wire connected to Rc
Yellow connected to Y
Orange wire connected to W
Green wire connected to G
The blue wire & white wire are not connected to anything & there are 2 outlets with nothing connected to them & they say R & not used.

Additional Details

I do have a button that says cool, heat, & off but only the AC works right now. I dont get paid until November 11th so I just cannot afford to call anyone to fix it at this time :(

Answer 1

Turn the power off to the furnace. Then install a jumper wire from Rc to R. This wire will need to be hooked to both and that should fix it. Then you can turn the furnace back on

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Answer 2

Set System Setting
Press the System button to select Heat, Off or Cool:
Heat—Thermostat controls the heating system.
Off—Both the heating and cooling systems are off.
Cool—Thermostat controls the cooling system.

Source(s):

http://www.instructionsmanuals.com/u2/pdf/termostato/Honeywell-RTH5100B-en.pdf

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Answer 3

It sounds like the best thing to do is call an HVAC person over to put the correct thermostat in. The guy that came over the house probably had to disconnect the heat wires and connect the ac wires, now you have to switch them back. This is not the right wiring/thermostat. You should have a thermostat that has a switch on it, that says heat, cool, and/or auto.

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Answer 4

there should be a wire from rc to rh. rc is is control power for cooling and rh is control power for heating. there are some instances where this isnt the case, if you have a different system for heating than cooling, but if all you have is a furnace with a cooling coil on top this should fix your problem

Source(s):

13 years hvac tech

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