Checked thermostat first and got nothing to come on,had no 24v to the outside unit.checked the unit inside and replaced the transformer,unit ran ok for couple of days then went out again.I replaced the transformer again,this time when I turn the power on to the unit it buzzes like it is wanting to come on,I think I may have wired the transformer up wrong.
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you have 24 volt across both terminals of contactor coil? if not and condenser is still running then you have a stuck contactor. also this is a heat pump so you have 24v and common going to out side unit and rodents or dogs may have chewed up wire and causing a short making connection and this would have blew transformer. FYI installing a 3 amp car fuse(spade type) installed in line of 24v coming off transformer will protect transformer as well as other components. your T-Stat may be defective as well.
if nothing comes on (on the outside unit) when you turn on AC (and the inside unit runs ok) I would check the fuses and/or the breaker for the outside unit. I would suspect a fuse blown or a breaker tripped. It's also possible that your 'low voltage' (24V) thermostat wire has been cut (by lawn mower) or chewed into (by dog). If the problem is the low voltage wire you can easily splice it back together - just be sure all power is off.
getting heat in the cooling mode leans toward the reversing valve in the outside unit. it changes the flow of refergerint so that the hot air you get outside in the summer is blown inside in the winter. another possibility is that the reversing valve isn't getting 24v check to see if you have 24v at O and C either at the t-stat, furnace, or the outside unit. if you check at the furnace rember the safty switch for the lower door if that switch is open you will have no power. i would look at the t stat first if you have 24v there go to the outside . 24v present outside will mean a bad valve or board, no 24v means a bad or broken conection in the control wire between the stat and the outside unit(usally the orange wire)
outside unit L1 and L2 are load (input 240vac) then you have control voltage, usually yellow and blue (24vac) this connects to some 18/2 thermostat wire which goes inside as white and red.
note: this unit may only need 24v control which is 2 wires from the inside unit and also 3 wires 2 hot 1 ground for line voltage.
STANDARD WIRING on the inside unit you have green, white, blue and red control wires.
on your thermostat you have white, red, yellow and green
you run the wire from the outside unit to the inside unit. then run a 18/4 wire to the thermostat if wired and join the following wires.
inside unit thermostat outside unit green------------------------green white-------------------------white red----------------------------red blue-------------------------------------------------------blue yellow--------------------yellow
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
This solution is based on a non-heat pump split system (furnace inside and condensing unit outside). The relay takes 24vac to energize and pull in closing the high voltage circuit to the compressor and condenser fan. If 24vac is present at the coil (two side terminals with smaller wire) and the relay does not pull in you need a new one. If no 24v is present then the outside unit is not getting the signal from the furnace and thermostat. If you pop off the furnace covers and access the control board your wires that go outside land on terminals C and Y. Y should have two wires, one from the thermostat and and the second goes to the outside unit. Test for 24v between C and Y. You must bypass the safety switch on the door prior to testing because that switch will cut off the power to the furnace. If nothing then you have a thermostat problem. If voltage is present you have a wiring issue between the furnace and outside unit.
transformer has just 4 leads. 2 for primary which is your 110 volts and 2 for secondary which is supposed to be 24 volts ac. if you splice the two secondary wires coming out of your transformer, you should be able to get a 24 v ac there.
the box that you are referring to could be a fire controller that in case of fire, it would shut off the fan and the compressor outside.
What you have is a 24v control circuit problem. There is a transformer in the air handler ( inside unit ) you will have 220v on the one side and 24v on the other. If you have 24v from transform there is a small fuse on the pc board that could blow during power problems. On the inside cover you should find a wiring diagram.
you lost your 24v check the transformer at the furnace at R and C treminals see if you have 24v if not your transformer is gone but you also have to have the door switch on the blower section closed and check incoming power as well
Your old stat is wired for a traditional thermostat and not a communication stat like the new infinity you have. There is a module plug on the furnace board that will need to be connected to the new thermostat for it to work. The wires that are wired now are from a terminal strip inside the furnace. Please contact your local Carrier dealer. They may be able to get that harness for you