No heat in Chevy

I have a 2014 Chevy Equinox and the blower doesn’t blow hot air- no heat, just cold air. The AC appears to be working fine.
I changed the thermostat. The coolant was changed 25K miles ago and is full.
The dials work fine as far as blower speed. The exiting hose from the heater core is warm.
No fluid leaks or smell of coolant. The blend door actuator isn’t making any noises, I took it out- it seems to be moving fine. I am not sure how to really test that. The temp gauge is at about 7 oclock which I think is normal for the vehicle. Can a bad coolant sensor cause this problem of no heat? There isn’t an engine light present. Maybe the heater core is partially clogged, if that’s even possible? Not sure what else to check. Any suggestions? Thank you.

Rotate the blend door manually, does it move from full cold to full hot? Does the air temperature change?

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Did this happen over time or over night???

No worries, summer is coming.


Define “warm “ heater core hose? My equinox hoses are both hot. To the point I almost can’t grip them without wincing. Warm means you have a heater core blockage. You need to flush the heater core. Not the cooling system. The heater core.

Overnight. Thanks for the response.

Thanks for the response. I’ll try that.

The houe coming out wasnt as hot as the one going in. Maybe a blockage? Thanks for the response.

Ill try that. Thanks for the response.

Heater core is always hot. Temp dial opens/closes flapper door under dash. It redirects air flow. If dash is set to cold then no heat is being sucked out of heater core. So, hoses in engine compartment should both be hot. Blend door? Maybe. Heater core, maybe. Cooling system? Maybe

Check the temps of the core hoses; you can buy a handheld thermal laser thermometer unit for less than $10.

You can do it by hand also…

With the engine at temp and running, heater fan off, the input and output hoses should be really hot, ~200 degrees, and too hot to hold.

Turn the heat on high, the input should still be hot while the output should be noticeably cooler like ~160 degrees. Edit: It the output is really cool, like ~90 degrees, that’s an indicator of a partially plugged core. Hot water is coming in and moving so slowly through the core that most of the heat is extracted before it exits.

If that’s not what you find, then your core is plugged; forward and back flush it with low pressure. Check youtube. I’ve seen people pull both hoses, drain out the water (1g shop vac) and fill the core with a radiator cleaner. Leave that overnight and then flush.

Definitely a possibility. Good ideas from poster above. Most posters here say both hoses feel about the same temperature when heater is working properly. It would be pretty unusual to have a plugged heater core in a 2014 model if the cooling system were flushed and coolant replaced every 2-3 years. Was it?

Another good idea from a different poster above is to manually configure the hvac doors in heat mode to prove/disprove the theory they aren’t being properly configured by the hvac system. Problematic hvac doors is a common complaint here.

Many scan tools, even the less expensive versions, have the ability to read the coolant temperature. If you have access to one of those, post what it says here, at a time coolant should be at normal operating temperature. Usually in the 200-215 degree F range. Since you replaced the thermostat, incorrect coolant temp seems unlikely.

One more idea, sometimes the heater core gets an air bubble in it, which prevents full flow. Usually that would occur b/c of a cooling system leak that was repaired, but the cooling system wasn’t bled of remaining air. Do you hear any weird sounds that seem to be coming from the heater core? Sounds like water running?