This procedure covers the removal and replacement of the heater control valve on a 2014 Ram 2500 with the 6.7L Cummins diesel engine, including coolant drain and refill procedures.

Warnings

Tools required

Parts

• Heater control valve × 1 — Use OEM specification
• Heater hose clamps (if reuse is not possible) × 2 — Use OEM specification

Fluids

• Mopar OAT Coolant (Purple) — 2 qt

Preparation

1. Ensure engine is completely cool to the touch (minimum 2 hours after operation)
2. Park vehicle on level surface and engage parking brake
3. Place drain pan under radiator drain valve location
4. Verify replacement heater control valve matches original valve configuration
5. Have adequate coolant supply available for refilling system

Procedure

1. 1

   Drain cooling system
   Open the radiator drain valve located at the bottom of the radiator on the driver's side. Drain approximately 2 gallons of coolant into the drain pan. Once coolant flow slows to a drip, close the drain valve. This partial drain is sufficient for heater control valve replacement without complete system drainage.
2. 2

   Locate heater control valve
   The heater control valve is mounted on the firewall on the passenger side of the engine compartment, in the heater hose line between the engine and the heater core. It is positioned near the A/C accumulator and has two heater hoses connected to it with clamps.
3. 3

   Disconnect electrical connector
   Press the release tab on the electrical connector attached to the heater control valve and carefully pull the connector straight off. Do not pull on the wiring harness itself. Inspect the connector terminals for corrosion or damage.
4. 4

   Remove inlet hose clamp and hose
   Using hose clamp pliers, compress or loosen the spring clamp or worm-drive clamp on the inlet heater hose (coming from the engine). Slide the clamp back on the hose away from the valve. Twist the hose gently to break any seal, then pull the hose off the valve nipple. Be prepared for coolant spillage. Position the hose upward to minimize coolant loss.
5. 5

   Remove outlet hose clamp and hose
   Repeat the same process for the outlet heater hose (going to the heater core). Compress or loosen the clamp, slide it back on the hose, twist and remove the hose from the valve. Allow any remaining coolant to drain into the pan.
6. 6

   Remove heater control valve mounting hardware
   Remove the mounting bolt or bracket that secures the heater control valve to the firewall. The valve may be held by a single bolt or a bracket assembly. Keep hardware for reinstallation. Remove the old heater control valve from the vehicle.
   Torque spec

   Valve Mounting8 Nm (6 lb-ft)
7. 7

   Prepare and install new heater control valve
   Inspect the heater hose ends for cracks, hardening, or damage. If hoses show wear, replace them. Position the new heater control valve in the mounting location on the firewall, ensuring correct orientation with the inlet port toward the engine side. The valve should have an arrow indicating flow direction.
8. 8

   Secure valve to mounting bracket
   Install the mounting bolt or bracket hardware and torque to specification. Ensure the valve is firmly mounted and properly positioned for hose connection without strain or kinking.
   Torque spec

   Valve Mounting8 Nm (6 lb-ft)
9. 9

   Connect heater hoses
   Push the inlet heater hose firmly onto the inlet nipple of the new valve until it seats completely. Slide the hose clamp into position over the connection point. Repeat for the outlet hose. Ensure both hoses are fully seated on the valve nipples before positioning clamps.
10. 10

    Secure hose clamps
    Position hose clamps approximately 1/4 inch from the end of each hose connection. If using worm-drive clamps, tighten to specification using a socket or nut driver. Ensure clamps are centered on the hose bead and not twisted.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
11. 11

    Reconnect electrical connector
    Plug the electrical connector onto the new heater control valve until it clicks into place. Gently tug on the connector to verify it is fully locked. Ensure no wires are pinched or under strain.
12. 12

    Refill cooling system
    Using Mopar OAT (purple) coolant, refill the cooling system through the radiator cap or coolant reservoir until the level reaches the cold fill line. Start with a 50/50 mix of coolant and distilled water. Add approximately 2 quarts to replace what was drained.
13. 13

    Bleed cooling system
    Start the engine and allow it to reach normal operating temperature with the heater set to maximum heat and fan on high. Monitor coolant level and add as needed while the system purges air. Watch for leaks around the heater control valve connections. Once the engine reaches operating temperature and the thermostat opens, the upper radiator hose should become hot. Add additional coolant as the level drops during bleeding.
    ⚠Do not remove radiator cap while engine is hot or pressurized. Allow system to cool before removing cap to add coolant.
14. 14

    Final coolant level adjustment
    After the engine has cooled completely, check the coolant level in the reservoir. Add coolant as necessary to bring the level to the cold fill mark. Install the reservoir cap securely.

Reassembly

1. Double-check all hose clamps are properly tightened and positioned
2. Verify electrical connector is fully seated and locked
3. Confirm no tools or parts were left in the engine compartment
4. Wipe down any coolant spills from engine components and firewall

Verification

• Start engine and verify heat output from cabin vents reaches normal temperature within 10-15 minutes
• Check for coolant leaks at heater control valve connections while engine is at operating temperature
• Verify coolant level remains stable in reservoir after test drive
• Confirm no coolant odor in cabin or visible steam from engine compartment
• Test heater temperature control operates smoothly from cold to hot settings
• Check for diagnostic trouble codes related to heater control valve operation

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