Parts for your 2017 Holden Colorado-Heater tap

2017 Holden Colorado heater tap — does it have one?

Short answer: no, the 2017 Holden Colorado (RG series) isn’t fitted with a heater tap. Factory technical information for the RG Colorado’s HVAC system shows a constant-flow heater core with temperature managed by an internal air‑mix (blend) door, not a coolant shut-off valve. Likewise, the OEM parts listings for the 2017 VIN ranges show heater core, pipes and hoses, but no heater control valve/tap as a serviceable component. That design approach is common across modern GM/Holden platforms of this era.

Why no heater tap? The Colorado’s climate system is set up so engine coolant continuously circulates through the heater core. Cabin temperature is then controlled by directing more or less air across that hot core via a blend door and actuator. This layout reduces leak points, simplifies the cooling circuit, speeds up demisting on cold, damp mornings, and helps maintain stable engine temperatures. It also means there’s one less under‑bonnet valve to seize, crack or drip on a long run out bush.

Chasing heating or demisting issues on a 2017 Colorado and thinking “heater tap”? Not the right part. Instead, the usual suspects are:

• Low coolant, old coolant, or air trapped after a service
• Partially blocked heater core or kinked hoses
• Faulty blend-door actuator or HVAC control issue
• Thermostat stuck open (engine runs too cool)
• Blower or airflow faults (including a clogged cabin filter where fitted)

For servicing, focus on proper coolant strength and change intervals, bleed the system correctly after any cooling work, and scan the HVAC for actuator faults if the temperature won’t swing from cold to hot. If heat is weak at idle but improves with revs, look for air in the system or a flow restriction rather than hunting for a non‑existent heater tap.

FAQs

Does a 2017 Holden Colorado have a heater tap?
No. The RG Colorado uses a constant‑flow heater core and an air‑mix (blend) door to regulate cabin temperature. There’s no coolant shut‑off valve in the heater circuit on this model year.

How is cabin heat controlled without a heater tap?
A small electric actuator moves a blend door inside the HVAC box to route more or less air across the hot heater core. That’s how the ute goes from chilly to toasty without ever turning coolant flow on or off.

What should be checked if there’s no cabin heat?
Start with coolant level/condition and make sure the system’s bled properly. If that’s good, check for a blocked heater core or hoses, thermostat performance, and whether the blend‑door actuator is moving as commanded. A quick fault scan can save heaps of guesswork.