No heat on 2015 Hard Rock Unlimited with auto climate control

HardRockEHS

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I've looked over existing threads to no avail. I have had no work performed on the Jeep other than my Oil Changes and Tire rotations in the past 2 years. The Climate control works perfectly for cooling but this morning we were leaving the Mountains in Virginia and it was cold enough to need heat which never showed up? Even on manual hot blowing on the floor and or defrost there was no hot air. Has anyone here run into similar issues? Thanks in advance!
 
Could be the blend door not working, or an issue with the heater core.

If this is the first time in quite awhile that you have turned on the heat it is possible that the heater core is blocked up. A heater core flush is super easy to do. Disconnect both input and output of the core. A garden hose to the output of the heater core and run it for a few mins, then switch to the input and do that. flop back and forth a few times if it is not flowing well.
Or there is air in the heater core, something that will need to be addressed after a core flush anyway.

To purge air in the system park pointing uphill or jack up the front end and with the radiator cap off run the engine. You need keep the radiator topped off, and do this until you get hot air.
NOTE: the clear bottle of coolant is not where you add coolant to the system. That is the overflow and will only function if there is enough coolant already in the system. Add it directly to the radiator. Don't open the radiator cap of a hot engine.
 
I've looked over existing threads to no avail. I have had no work performed on the Jeep other than my Oil Changes and Tire rotations in the past 2 years. The Climate control works perfectly for cooling but this morning we were leaving the Mountains in Virginia and it was cold enough to need heat which never showed up? Even on manual hot blowing on the floor and or defrost there was no hot air. Has anyone here run into similar issues? Thanks in advance!

Get the engine up to operating temp and carefully feel the two hoses going to and from the heater core. Hot coolant goes into the core in one hose, and comes out the other. Both should be about the same temp. If not, you may have a heater core blocked up and need a flush or to replace it.

If that's not it, there are two other things that can cause it. Either your selector knob inside the cabin, or the blend door actuator.

There are videos out there that cover all of this if you search on them.
 
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Get the engine up to operating temp and carefully feel the two hoses going to and from the heater core. Hot coolant goes into the core in one hose, and comes out the other. Both should be about the same temp. If not, you may have a heater core blocked up and need a flush or to replace it.

If that's not it, there are two other things that can cause it. Either your selector knob inside the cabin, or the blend door actuator.

There are videos out there that cover all of this if you search on them.
Great Tip! Thanks!
 
Could be the blend door not working, or an issue with the heater core.

If this is the first time in quite awhile that you have turned on the heat it is possible that the heater core is blocked up. A heater core flush is super easy to do. Disconnect both input and output of the core. A garden hose to the output of the heater core and run it for a few mins, then switch to the input and do that. flop back and forth a few times if it is not flowing well.
Or there is air in the heater core, something that will need to be addressed after a core flush anyway.

To purge air in the system park pointing uphill or jack up the front end and with the radiator cap off run the engine. You need keep the radiator topped off, and do this until you get hot air.
NOTE: the clear bottle of coolant is not where you add coolant to the system. That is the overflow and will only function if there is enough coolant already in the system. Add it directly to the radiator. Don't open the radiator cap of a hot engine.
Just watched a few youtube vids and I'm getting ready to go diagnose. I'll update later with results. Thanks all!
 
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You have two locations where things can go wrong. One is under the hood and serious. Check to be sure that when the engine is up to temperature, that the hose that circulate hot coolant through the heater are warm. If they aren't, you might want to check your radiator core. Otherwise, the most likely cause is the blend door inside the cab. No heat in JKs seems to be a pretty common complaint.
 
Ok... Its not a blocked heater core.. I've flushed that and it was clear. I have confirmed hot water on the input and output sides of the core. I have the Auto Climate control and if I take it off Auto, Run it up to high air flow and then run through the various mix options for the air from dash to floor to floor and defrost it moves perfectly through the various output options flawlessly only with cold air. the problem has to be with the climate thermostat in some way? Do any of you have thoughts?
 
Ok... Its not a blocked heater core.. I've flushed that and it was clear. I have confirmed hot water on the input and output sides of the core. I have the Auto Climate control and if I take it off Auto, Run it up to high air flow and then run through the various mix options for the air from dash to floor to floor and defrost it moves perfectly through the various output options flawlessly only with cold air. the problem has to be with the climate thermostat in some way? Do any of you have thoughts?

Did you check the blend door actuator?

You can actually watch the plastic arm move as you switch between hot/cold selections to switch from hot to cold.

I bet it's either stuck or the actuator is bad.
 
yep, there are two "doors" one for where the air is going (which vents) and one for where it is coming from (hot or cold) Almost certainly the hot/ cold one isn't functioning given that you have verified the heater core is flowing.
 
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