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Hello, try taking the tstat off the wall and disconnecting the wires, if this turns off ac then you have a bad tstat. If not then the relay on the control board is defective and the board must be replaced. If you are just referring to the outside unit running non stop then tne contactor coil is defevtive and must be replaced.
Hello, check the tstat wiring going to the unit for any breaks in or if it has come loose between the indoor unit and outdoor unit. Also, chevk if you are getting voltage from tje control board between the y and c terminal, if not the control board is bad. Last thing to check is remove tstat and jump the y and r wires there if this starts the unit then you have a bad tstat.
Sounds like a bad tstat. The Tstat does control the on and off of the unit.
You can check the Tstat by taking off the white wire to the tstat and turning the heat to the on position and if it still comes on you have a bad wire. If it does not come on then you have a bad tstat.
Another option is to open the furnace and look inside at the control wires and follow them back to ensure that they are not shorted together anywhere inside the unit before checking the tstat wires.
If its the control wires then follow option 1 if not follow option 2.
1.Normally people who run tstat wire pull more wires than necessary to the tstat. Because of this you can use a different one for the heat which is white on the tstat. Remember that if you use another color on this then you need to change it on the inside unit as well. Otherwise it will not work. In other words change it on one end of the line you have to change it on the other to make it work.
To check the tstat wires, use continuity. Take all the wires off the tstat and the inside unit. These are the small control wires, not the main 110 wires. Check each one against each other to see if any of them are shorted together. Be sure to write down the wire colors and the terminals that they belong to on both sides before you take them off otherwise you will have big problems...
If you do not have another wire then pulling a new wire will be the next option.
2. If this does not solve it, then its the TSTAT, Replace it.
Hope this helps.
Hi; Need more info. How old is the equipment,look on the outside unit data plate it will give the built date usually in the top right corner. Also heat pumps can run with a faulty defrost board. I would check for control voltage at the secondary side of the transformer should be atleast 24 volts ac. Also the test post on the defrost board are for troubleshooting a defrost problem not an operational problem.When the posts are temporarely shorted the condensor will go into a defrost cycle This step will let the tech. know if defrost is operating normally. Also I have seen a reset switch manualy reset but not reinergize the control voltage. Also the outdoor unit has a delay timer that will wait for freon press. to equalize befor letting the unit operate. One more thing do You now if Your tstat is operating normally. One more idea is the defrost sensor if faulty it can leave the condensor in a defrost state of operation. This intern will sometimes go to heat strips because they are used in the defrost cycle to warm up the air conditioning going on durring a defrost cycle. One more thought is does the control contactor have 24 to 27 volts going to it if so replace the contactor. To test this using a voltage meter and touch after waiting 5 min. both sides of the coil. Remember voltage is deadly so ..When in doubt call a qualified tech.I ASSUME NO LIABILITY FOR INJURIES TO YOU OR THE EQUIPMENT BE CAREFULL!!! IF YOU GROUND YOURSELF BETWEEN 230VOLTS THIS BE VERY BAD...alpharome416
If you turn tstat off does it still run. If so you have sequencer stuck. Replace sequencer. Also you may ahve abad defrost board out side. When a unit goes into defrost it will bring on heat so you will not get a blast of cold air. Sometimes the defrost board sticks and keps the heat on. Disconnect white wire at outside unit to break circiut. If hat goes off bad defrost board. You can change that yourself. Keep in touch Rus
that seems like too long at most delays and lock outs that are built into a system throught the tstat and the outdoor systems defrost board should only take about ten minutes. at most twenty if you had a dual fuel system. (heat pump outside and gas furnace inside). check the installer programming on your tstat may have a compressor lock out set too long for some reason.that or possible bad lowvoltage connections or maybe ants in you contacts at compressor outside. could be many things
hey there, it seems you know a little about the troubleshootig. The first thing you need to do is see if the rela is trying to energize by checking for 24v accross the coil while it should be running. I am guessing that with a 1/8 hp this is the condenser fan motor (outside). If you are not getting 24v at the coil is your compressor coming on? You may have a safety switch with a manual reset (usually red button) on the piping under the fan motor or just a broken wire. If this is a heat pump and the relay is located on the circuit board and the compressor is coming on,chances are the board is bad. If you only have 2 stat wires coming into the unit, check for 24v on them wait for any time delays. If it is there and at the coil replace the relay. If the 24v is not outside at all, check iside or try different collor wires, one may be broken. If still no 24v, take the tstat off the wall, turn off both units to kill power, twist the wires from terminals G, Y and R together. This should bring it on. If this is the only way to bring it on, replace the tstat. Also, there may be a float switch in a condensate pan somewhere on the indoor unit. If the pan is filled with water, it will either kill the whole 24v circuit or just keep the outdoor from coming on. Let me know what you find seth
Did you replace the defrost board out in the outside unit? Or did you replace the control board just on the airhandler? You need to check if the board outside is functioning. Also, put the unit in cool and check to see if the outside unit is being called to come on. What could of happened is the unit was the compressor went out and that's why it didn't work in Aux. and only in emergency. I would just recommend checking the outside for issues since the inside unit is operating in emer. It could possibly be the tstat also. Just buy a tstat for a heat pump and follow the instructions. The key is to label your wires with what color is going to what terminal (r,w,g,o,y etc...) and then use the new tstat instructions. Better yet, buy the same brand t-stat. Hope this helps.