This procedure removes and replaces the heater core assembly in a 2022 Rivian EDV 500, requiring partial dashboard disassembly and coolant system drainage.

Warnings

Tools required

Parts

• Heater core assembly × 1 — Use OEM Rivian specification
• Heater core inlet/outlet O-rings × 2 — Use OEM Rivian specification
• HVAC housing seal gasket × 1 — Use OEM Rivian specification
• Push-pin fasteners (assorted) × 10 — Use OEM specification

Fluids

• EV Battery/Motor Coolant — 10 qt

Preparation

1. Park vehicle on level surface and apply parking brake
2. Ensure vehicle has been off for at least 2 hours to allow coolant system to cool completely
3. Open hood and locate the high-voltage service disconnect panel behind the front storage compartment
4. Remove service disconnect following Rivian safety protocol and store in a secure location away from vehicle
5. Wait minimum 3 minutes for high-voltage capacitors to discharge
6. Disconnect 12V auxiliary battery negative terminal
7. Place fender covers and interior protective coverings to prevent damage during disassembly
8. Position coolant drain pan under front of vehicle beneath coolant hose connections

Procedure

1. 1

   Drain coolant system
   Locate the coolant drain valve on the driver-side lower radiator connection. Open the drain valve and allow coolant to drain into collection pan. Remove the coolant reservoir cap to allow complete drainage. Collect and store used coolant in sealed container for proper disposal or reuse if uncontaminated.
2. 2

   Remove lower dashboard panels
   Remove the driver-side lower dashboard trim panel by releasing 6 push-pin fasteners and disconnecting the hood release cable. Remove the center lower console panel by releasing 4 push-pin fasteners. Remove passenger-side lower dashboard panel using trim removal tools to release 8 clips along perimeter.
3. 3

   Disconnect HVAC electrical connectors
   Locate the HVAC control module below the center stack. Disconnect the main HVAC harness connector by pressing the locking tab and pulling straight back. Disconnect the blower motor connector and heater core temperature sensor connector. Take photos of routing before disconnection.
4. 4

   Remove center console and display assembly
   Remove 4 T30 Torx screws securing the center display assembly. Carefully pull the display forward and disconnect the three harness connectors on the rear. Support the display and set aside on protected surface. Remove center console storage bin by releasing 6 clips and disconnecting USB port connectors.
5. 5

   Access heater core hose connections
   Working from the engine compartment, locate the heater core inlet and outlet hoses on the passenger side of the HVAC housing near the firewall. Use hose clamp pliers to reposition spring clamps away from connection points. Carefully twist and pull hoses from heater core tubes. Immediately cap or plug open connections with plastic bags secured with zip ties to prevent coolant spillage.
6. 6

   Remove HVAC housing fasteners
   From inside the vehicle, remove 8 T25 Torx screws securing the HVAC housing to the firewall and support brackets. Remove 2 additional 10mm nuts on the passenger side accessible through the lower dashboard opening. Note the location of different length fasteners for reassembly.
7. 7

   Separate HVAC housing sections
   Locate the 6 clips securing the upper and lower HVAC housing halves. Using a trim tool, carefully release each clip working from bottom to top. Gently separate the housing halves, being careful not to damage the mode door actuators or blend door linkages attached to the upper housing.
8. 8

   Remove heater core assembly
   With the lower housing section accessible, locate the heater core retention bracket secured by 2 T20 Torx screws. Remove screws and bracket. Carefully slide the heater core assembly out of the housing, noting the orientation of inlet/outlet tubes. Remove and discard old O-rings from heater core tubes.
9. 9

   Prepare and install new heater core
   Inspect the HVAC housing for debris, leaves, or signs of coolant contamination. Clean housing interior if necessary. Lubricate new O-rings with fresh coolant and install onto new heater core inlet and outlet tubes. Verify the heater core tube orientation matches the original, then carefully slide the new heater core into the housing until fully seated.
10. 10

    Reinstall retention bracket and close housing
    Install the heater core retention bracket and secure with 2 T20 Torx screws. Apply new seal gasket to the lower housing mating surface if equipped. Align the upper and lower housing halves, ensuring all door linkages and actuator shafts engage properly. Press housing halves together until all 6 clips audibly snap into place.
11. 11

    Reinstall HVAC housing assembly
    Position the complete HVAC housing assembly against the firewall, aligning mounting points. Install and hand-tighten 8 T25 Torx screws and 2 10mm nuts. Tighten fasteners in a cross pattern to ensure even sealing against the firewall.
12. 12

    Reconnect heater hoses
    Working from the engine compartment, remove protective bags from heater core tubes. Inspect hoses for damage or deterioration and replace if necessary. Push hoses firmly onto heater core tubes until they seat completely. Reposition spring clamps to secure hoses 1/4 inch from tube ends.
13. 13

    Reconnect electrical components
    Reconnect the heater core temperature sensor, blower motor connector, and main HVAC harness connector. Ensure all connectors lock securely. Verify no wiring is pinched or routed incorrectly by comparing to reference photos taken during disassembly.
14. 14

    Refill and bleed coolant system
    Close the coolant drain valve. Pour EV Battery/Motor Coolant into the coolant reservoir to the FULL mark. If available, use a vacuum-fill tool to ensure complete filling and eliminate air pockets. If filling by gravity, start the vehicle climate system and allow heater to run while monitoring coolant level, adding coolant as air is purged from the system. Run climate system through all temperature settings and verify hot air output.

Reassembly

1. Reinstall center console storage bin and reconnect USB port connectors
2. Reinstall center display assembly and secure with 4 T30 Torx screws, reconnecting all three harness connectors
3. Reinstall passenger-side, center, and driver-side lower dashboard panels, ensuring all clips engage properly
4. Reconnect hood release cable to driver-side panel
5. Replace any damaged push-pin fasteners with new units
6. Reconnect 12V auxiliary battery negative terminal
7. Reinstall high-voltage service disconnect following Rivian safety protocol

Verification

• Check for coolant leaks at heater core hose connections and around HVAC housing firewall seal
• Verify coolant level is at FULL mark after system reaches operating temperature
• Start vehicle and activate climate control system, testing all temperature settings from full cold to full hot
• Verify hot air output temperature is consistent and reaches expected cabin heating performance
• Check for unusual odors from HVAC vents that might indicate coolant leakage
• Verify all dashboard panels are secure with no rattles or gaps
• Test all HVAC modes (defrost, floor, vent, bi-level) to ensure proper operation
• Scan vehicle for diagnostic trouble codes using Rivian service software and clear any HVAC-related codes if present
• Monitor coolant level over the next several days and top off if necessary as residual air purges from system

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