DescriptionThis video provides step-by-step instructions for replacing the main control board on a Carrier/Gree ETAC Heat Pump Unit. The most common reason for replacing this part is if the unit is not working at all.
All of the information in this video is applicable to the following brands: Carrier, Gree
Step-By-Step Instructions1
To replace the main control board in this carrier/gree etac heat pump unit…
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… you will need a #2 phillips-head screwdriver, wire cutters, zip-ties, and a power drill with a 5/16th inch socket.
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Before you begin, be sure to turn the unit off…
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…and disconnect the power supply.
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When performing this procedure, you will need to fully uninstall the unit from the wall.
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… remove the unit’s front panel by pulling the bottom of the panel out to release it from the tabs…then lift up.
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If applicable, disconnect the thermostat wire connecter and the energy management wire connecter.
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Using the power drill with the 5/16th inch socket, unthread the four mounting screws securing the unit to the wall sleeve.
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Now have an assistant help you to slide the unit out of the sleeve…
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… and set it on a towel or blanket.
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Use the #2 phillips-head screwdriver to unthread the screw securing the control panel.
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Detach the control panel.
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Now unthread the lower right screw securing the junction box cover.
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Unthread the three screws securing the junction box itself.
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Pull back the cover to fully detach the junction box from the power cord.
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Disconnect the power cord wire connecter.
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Next, unthread the six screws securing the control box’s side access cover.
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Unthread the four screws to release the left access cover.
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Now unthread the five screws securing the middle access cover.
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Disconnect the relay board and transformer wire connecters from the main control board for better access to the board.
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Using the phillips-head screwdriver, unthread the two screws securing the main control board to it mounting plate.
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Detach the board from the plate.
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Use the wire cutters to cut the zip-tie bundling the wires together.
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Release the display board wire connecter locks…
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… then disconnect the two connecters.
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Cut the zip-ties securing the ambient temperature sensor wire and the indoor coil temperature sensor wire.
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Detach the ambient temperature sensor from the mounting brackets.
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Remove the indoor coil temperature sensor from its sleeve.
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Cut the zip-ties securing the outdoor coil temperature sensor wire…
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… release the wire from the retainer… and remove the sensor from its sleeve.
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Next, unthread the screw so you can detach the wire cover.
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Pull the outdoor coil temperature sensor through the access hole.
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Using the #2 phillips-head screwdriver, unthread the six screws securing the discharge air screen.
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Unthread the screws to detach the two support brackets securing the fan housing.
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Now unthread the remaining four screws to release the indoor blower cover.
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With the cover removed, cut the zip-tie securing the discharge air temperature sensor and remove the sensor from its sleeve.
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You can now fully remove the old main control board and sensors.
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To install the new main control board…
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… feed all the sensor wires and the display board wire connecters through the hole in the control box’s side panel.
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Now feed the discharge air temperature sensor into the indoor blower housing…
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… and the outdoor coil temperature sensor through the wire access hole.
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Insert the discharge air temperature sensor into its sleeve and use a new zip-tie to secure.
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Realign the baffle on the blower housing…
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… then reposition the indoor blower cover.
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Realign the two fan housing support brackets…
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… and secure them with the screws.
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Reposition the discharge air screen and rethread the six screws to secure.
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Now insert the outdoor coil temperature sensor in its sleeve… hook the wire in the retainer…
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… and use a new zip-ties to secure the wire.
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Replace the wire cover and thread the screw to secure.
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Insert the indoor coil temperature sensor into its sleeve…
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… then feed the ambient temperature sensor through the right mounting bracket and snap it into place in the middle bracket.
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Use new zip-ties to secure the sensor wires.
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Connect the two display board wire connecters…
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… and slide the locks into place to secure.
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Use a new zip-tie to bundle the wires together.
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Align the new control board on the mounting plate and thread the two screws.
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Connect the relay board and transformer wire connecters to the main control board…
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… then realign the middle access cover and thread the five screws.
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Reposition the left access cover…
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… and rethread the screws.
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Realign the side access cover…
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… and thread the screws to secure.
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Reconnect the power cord wire connecter…
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… then reposition the junction box and rethread the screws.
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Rethread the lower right screw to fully secure the cover.
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Realign the control panel and thread the screw to secure.
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Reinstall the unit by sliding it into the wall sleeve until the seal rests against the front of the sleeve.
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Rethread the mounting screws to secure the unit.
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Avoid over-tightening the screws.
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Reconnect the thermostat and energy management wire connecters if applicable.
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Reinstall the front panel by aligning the tabs over the top rail then push the bottom of the panel in until it snaps into place.
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Restore power to the unit…
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… and the etac heat pump system should be ready for use.