Posted: 5/15/2005 1:11:04 PM EDT
ETA:  OK, resurecting this... I installed a new thermostat, but all I'm (now) getting is 'uncooled' air, and warm air - the HEAT is working, but the cooling isn't. Any thoughts? |
OK, guys, getting awfully hot in here.  Here's what I've got... 4 wires. In the old unit, they are as follows... Rc G Y/W - This wire was hooked up to BOTH connections O Now, I can only get the stinking thing to kick on in HEATING mode. I've tried multiple variations on this, and it WILL NOT kick on in cooling mode. The Fan will kick on, but the A/C itself won't. Now, here's where I'm really fucking confused. On the new unit, there are the following connections... G - Good here Y W Rh Rc Now, according to the diagram, if I've only got Rh or Rc, I should link the two. No prob, I can handle that. But What the F*(k is O, and WTF should I do with Y and W? One is supposed to be heating, the other, cooling. I'm lost here... |
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Thermostat terminals are as follows. "O" is to energize the reversing valve in the cooling mode for a heatpump system. It must be hooked up to have cooling. Or the unit will run in heat only. Most manufactures energize the reversing valve in the cooling mode, so if the valve fails. It will fail to the heat mode. Only two manufactures do the opposite to fail to cool mode. That would be Goettle and Rhem/Ruud. As for these two they use the "B" terminal to energize the reversing valve in the heat mode. If you have gas heat, electric heat strips, oil burner, or propane heat. Terminals O and B will not be used. They are only for heatpumps. By National electric code Orange wire should go to O and Blue wire to B. R, RH, or RC = 24 volt from the transformer. If a stat only has R then that's all you use. If the stat has RH and RC, they will need to be jumpered together. RC= 24 volt for cooling. RH= 24 volt for heating. On real old systems (say 30 years old) had a transformer in the furnace and one in the outside A/C unit. This set up then would not have a jumper from RH to RC. They would have seperate wires. By national electrical code the wire should be Red. That takes care of the R's. G= Indoor blower relay. Also know as Fan On or Fan Auto. Most people keep it in Fan Auto. This way the indoor blower will cycle only when a demand for heat or cool is calling. If you turn it to Fan On, the indoor blower will always run. Some people do this to circulate air in the house. And will also continue to filter the air in the house. By National electric code this wire should be green. Y= Demand for cooling. This is what energizes the contactor, to apply high voltage to the compressor and outdoor fan motor. By National electric code this wire should be yellow. W= Demand for heating. This is what energizes all the different types of heating. Such as the contactor only for heatpumps. That's why a jumper must be between W and Y. Although on some new digital stats this jumper dosen't need to be. Because of the system settings on the thermostat. Like HP or NON-HP switch. Switch is usually on the back of the stat. It also energizes the gas valve. the furnace ignitioin board, or electric strip heat sequence. By National electric code this wire should be white. C=Common from the transformer. This must be hooked up for a stat that requires a common wire. Most stats today don't use common. Color of wire will more than likely be what ever installer had as a extra wire. Who know's. Y2= 2nd stage cooling. If you have a super high efficency unit with two stage cooling, like two speed compressor or two compressors. This terminal must have a wire. Once again color wire unknown. W2= 2nd stage heating. Mainly used for two stage gas valve systems or heatpumps that have secondary electric heat strips. This will help out the heatpump on cold days. Again wire color unkown. E= Emergency electric heat strips. This is mainly used for heatpumps in real cold enviroments. What it will do is turn off your heatpump and then use several electric heat strips only for heating. Hope this helps all you Do-It-Yourself guys. Print this just in case you need it. Your wife will laugh at you if you try to change the stat and can't figure it out. I'll also laugh at you when your wife calls me out to fix your screw up. Other notes. Most new digital stats have switches on the back that must be set for proper set up. Like the HP or Non-HP switch described above. Other switches will be F or C switch. This is for Farinheit or Celcus. Most people use F. One other switch is Gas or Elect. This switch is used for Gas in gas/propane heat and Elect for Electric heat strips or heatpumps. Other digital programmable stats have a installer set up that is done from the front of the stat after it's hooked up to power. This set up must be done by someone that knows what the fuck they are doing. Call me. Thanks and have fun. |