Parts for your 2017 Mitsubishi Eclipse cross-Heater tap

2017 Mitsubishi Eclipse Cross heater tap: not fitted, and that’s by design

For the 2017 Mitsubishi Eclipse Cross (GK series), a heater tap (also called a heater control valve or water cock) isn’t used. Technical references back this up: the Mitsubishi Motors Eclipse Cross Service Manual HVAC section shows a constant-flow heater circuit with temperature regulated by the air mix (blend) damper, not a water shut-off valve. Likewise, the Mitsubishi ASA electronic parts catalogue for GK models doesn’t list a heater control valve for the heater circuit, only hoses, pipes and the heater core. Wiring diagrams for the climate control also show blend-door actuators but no heater-tap solenoid or cable.

Why delete the heater tap? Modern climate systems in vehicles like the Eclipse Cross keep hot coolant flowing through the heater core at all times and adjust cabin temperature by blending cold and hot air with a damper. That approach delivers smoother temperature control, fewer leak points, simpler plumbing under the bonnet, and faster demist/defog performance because the core stays hot and ready. It also means one less valve to seize or drip on the firewall. Any minor heat-soak concerns in summer are handled by the air doors sealing off the core when maximum cooling is called for.

Because there’s no heater tap to service, owners and techs should focus on the usual cooling and HVAC maintenance items that actually affect heater performance:

• Follow the prescribed coolant service interval with the correct Mitsubishi Super Long Life Coolant (blue), bleeding air properly so the heater core fills.
• Check for low coolant, hose seepage, and heater-hose quick-connects at the firewall if there’s poor heat or a sweet smell inside.
• If cabin heat is weak but engine temperature is normal, consider a partially restricted heater core or trapped air, a backflush and correct bleed often restore performance.
• Temperature issues that change with vent selection commonly point to a blend-door actuator or calibration fault rather than anything in the coolant circuit.
• Replace the cabin filter on schedule—reduced airflow can make the heater feel underwhelming even when the core is hot.

If a parts listing shows a “heater tap” for the 2017 Eclipse Cross, it’s typically a generic or misapplied catalogue entry. The GK-series HVAC design simply doesn’t use one, so there’s nothing to replace there during servicing.

Popular questions about the 2017 Mitsubishi Eclipse Cross heater tap

Does the 2017 Eclipse Cross have a heater tap?
No. The GK Eclipse Cross uses constant coolant flow through the heater core and controls cabin temperature with an air mix damper. Mitsubishi’s service information and parts catalogue show no water shut-off valve in the heater circuit.

How is cabin temperature controlled without a heater tap?
The climate control blends air passing through (hot) and around (cool) the heater core using a motorised blend door. By varying that door position, the system fine-tunes outlet air temperature without ever stopping coolant flow.

What should be checked if heater output is weak?
Look for low coolant, air in the system, a partially clogged heater core, a stuck-open engine thermostat, a clogged cabin filter, or a faulty blend-door actuator. These are the usual culprits on vehicles without a heater tap.