Replacement of the heat pump assembly on a 2024 Model S Long Range AWD. This is a PROFESSIONAL-ONLY procedure: the heat pump is integrated into Tesla's combined battery/motor/cabin thermal loop via the octovalve, and Tesla Toolbox is required to safely depressurize and refill the system. Battery coolant inspection interval is 4 years / 50,000 mi per current Tesla guidance.

Warnings

Tools required

Parts

• Heat pump assembly (manufacturer-specified for 2024 Model S) × 1 — OEM Tesla heat pump assembly — verify by VIN
• Heat pump mounting seals / O-rings (refrigerant and coolant ports) × 1 — OEM seal kit supplied with heat pump
• Hose clamps (single-use spring clamps if equipped) × 4 — OEM-spec replacement clamps
• Cabin air filter (replace if due — 2-yr / 3-yr HEPA interval) × 1 — OEM Model S cabin filter set

Fluids

• Tesla Battery/Motor Coolant (G-48 equivalent) — 10 qt
• R-1234yf refrigerant (charge per underhood label)
• Refrigerant oil (PAG/POE per Tesla spec for electric A/C compressor)

Preparation

1. Park on level ground, place in P, engage parking brake.
2. Exit ALL doors with the key fob away from the vehicle. Wait at least 2 minutes for HV systems to fully de-energize, even on this non-HV job.
3. Disconnect the 12V low-voltage battery in the frunk under the nose cowl panel (verify 16V Li unit if present per VIN). Isolate and insulate the negative terminal.
4. DO NOT touch, cut, or pierce ANY orange cable — these are high-voltage and lethal.
5. If at any point you encounter an orange cable, an HV component, or are unsure if a system is de-energized: STOP and consult a Tesla-certified technician.
6. Connect Tesla Toolbox and command 'Service Mode' plus the thermal system depressurization / coolant service routine. Confirm the battery coolant loop is isolated and depressurized before opening any line.
7. Recover R-1234yf refrigerant from the A/C system using an approved recovery machine. Record the recovered weight.
8. Raise the vehicle on a lift using Tesla-approved lift pad locations. Remove the front underbody shield and any aero panels needed to access the heat pump area.
9. Remove the frunk liner and any cowl/cover panels required to access the heat pump assembly per the service manual.

Procedure

1. 1

   Verify thermal system is depressurized
   With Toolbox still connected, re-confirm that the battery coolant loop and refrigerant circuit show depressurized. Do not proceed if either circuit shows residual pressure.
   ⚠️Improperly handled coolant can enter the HV battery (~$15,000+ to replace). Do not open any line until Toolbox confirms depressurization.
2. 2

   Disconnect low-voltage connectors at the heat pump
   Locate the LV connectors and the temperature/pressure sensor harnesses on the heat pump assembly. Release the locking tabs and set the harness aside, supported, so it does not hang on the connectors.
3. 3

   Position drain pan and prepare to break the coolant loop
   Place a clean catch pan beneath the heat pump assembly. Have caps/plugs ready for every line you open. Label each hose with tape before disconnecting so reassembly orientation is unambiguous.
   ⚠️From this point on, any spilled coolant near HV components or connectors can damage the HV battery and create shock risk. Cap every line immediately after disconnection.
4. 4

   Disconnect coolant hoses from the heat pump
   Release the spring clamps (or threaded fittings, depending on port) and carefully pull each coolant hose from the heat pump ports. Plug each hose and each port immediately. Catch residual coolant in the pan. Do not reuse single-use spring clamps.
   ⚠️Coolant from this loop is shared with the HV battery cooling circuit. Contact with HV components can destroy the pack and cause a fire/shock hazard.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)

   Coolant Line Fittings15 Nm (11 lb-ft)
5. 5

   Disconnect refrigerant lines from the heat pump
   After confirming refrigerant has been fully recovered, remove the refrigerant line block fittings at the heat pump. Discard the O-rings; new ones must be installed at reassembly. Cap the open refrigerant ports immediately to prevent moisture ingress.
   ⚠Any moisture in the refrigerant circuit will require the receiver/drier to be replaced and the system fully evacuated for an extended cycle.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
6. 6

   Remove heat pump mounting hardware
   Support the heat pump assembly. Remove the bracket bolts and primary mounting bolts attaching the assembly to the body structure. Note shim or isolator locations for reuse.
   Torque spec

   Bracket Bolts20 Nm (15 lb-ft)

   Mounting Bolts27 Nm (20 lb-ft)
7. 7

   Extract the heat pump assembly
   Carefully lift the assembly out of the vehicle, keeping it level to avoid spilling residual coolant. Place on a clean bench. Inspect the mounting area for damage, debris, or signs of prior leakage.
   ⚠️Tipping the unit can release trapped coolant onto adjacent HV harnesses. Keep the assembly level until drained into the catch pan.
8. 8

   Transfer sensors and brackets to the new unit (if required)
   If the replacement heat pump does not ship with sensors/brackets pre-installed, transfer them from the original unit using new seals where applicable. Torque sensor fasteners and brackets to spec.
   Torque spec

   Sensor Bolts11 Nm (8 lb-ft)

   Bracket Bolts20 Nm (15 lb-ft)

   Cover Screws11 Nm (8 lb-ft)
9. 9

   Install new heat pump assembly
   Position the new heat pump in the vehicle and start all mounting bolts by hand. Once aligned, torque the primary mounting bolts and bracket hardware to specification.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)

   Bracket Bolts20 Nm (15 lb-ft)
10. 10

    Reconnect refrigerant lines
    Install new O-rings lubricated with the correct refrigerant oil. Seat the line blocks squarely against the heat pump ports and torque the block fasteners to OEM specification — refer to Tesla Service Manual for the refrigerant block torque, which is not in the verified list.
    ⚠Cross-threading or over-torquing the aluminum refrigerant block will cause leaks that are very difficult to diagnose later.
11. 11

    Reconnect coolant hoses
    Install new clamps where required. Seat each hose fully on its port and position the clamp in the factory location. Torque threaded coolant fittings and hose clamps to spec.
    ⚠️A weeping coolant joint can route fluid into the HV battery enclosure. Verify every clamp position and orientation before refilling.
    Torque spec

    Coolant Line Fittings15 Nm (11 lb-ft)

    Hose Clamps3 Nm (2 lb-ft)
12. 12

    Reconnect low-voltage harnesses
    Reseat each LV connector until it clicks and verify the secondary lock is engaged. Route the harness back into its original clips so it cannot chafe on coolant or refrigerant lines.
13. 13

    Vacuum and recharge the refrigerant system
    Pull a deep vacuum on the A/C system per Tesla specification and hold to verify no leaks. Recharge with R-1234yf to the weight specified on the underhood label, adding refrigerant oil per Tesla's service procedure for component replacement.
    ⚠Insufficient vacuum hold time will leave moisture in the system and damage the electric A/C compressor.
14. 14

    Refill and bleed the coolant system using Toolbox
    Reconnect 12V. With Toolbox, run the coolant fill / bleed routine, which sequences the octovalve and pumps to purge air from the battery, drive unit, and cabin loops. Add Tesla-spec G-48 coolant as the system draws it down. Do not substitute conventional coolant.
    ⚠️Skipping the Toolbox-driven bleed leaves air pockets in the battery loop, which causes localized overheating and can damage HV cells.
    Torque spec

    Cover Screws11 Nm (8 lb-ft)
15. 15

    Functional test of heat pump and thermal system
    With the vehicle in Service Mode, run thermal system self-tests: cabin heat, cabin A/C, battery conditioning, and Supercharger preconditioning if available. Monitor coolant pressures and temperatures via Toolbox for at least one full preconditioning cycle.

Reassembly

1. Reinstall any cowl panels, frunk liner, and underbody aero shields that were removed for access.
2. Reinstall the 12V battery cover and verify the low-voltage battery is securely terminated (or 16V Li unit if equipped).
3. Lower the vehicle and remove lift pads.
4. Clear any DTCs in Toolbox after the test cycle and exit Service Mode.
5. Wipe down all coolant residue and dispose of used coolant and refrigerant per local regulations.

Verification

• Confirm zero refrigerant leaks with an electronic R-1234yf leak detector at every disturbed joint.
• Confirm zero coolant weeping at every disturbed clamp/fitting after a full thermal cycle.
• In Toolbox, verify battery inlet/outlet coolant temperatures track within spec during a battery conditioning cycle.
• Verify cabin heat reaches normal output at idle within manufacturer-specified time, and cabin A/C reaches expected vent temperature.
• Test Supercharger preconditioning by routing to a Supercharger in the nav — the pack should begin warming/cooling within a few minutes.
• Document the coolant service date; next battery coolant inspection is due in 4 years or 50,000 miles, whichever comes first.
• If the cabin filter is older than 2 years (or 3 years for HEPA-equipped cars), replace it while service records are open.

More procedures for this vehicle