Heater blows cold air

Hello -

To better assist you is your model the Cherokee Classic, Limited, SE, Sport, Grand Cherokee Laredo or Grand Limited and what is the engine size in liter.
Do both heater hoses get hot when the engine is warmed up? If so this is an indicator that the flow is there and you may have a blend door issue. For this we will definitely need to know which Jeep you have as the Cherokee and Grands are vastly different

Read this guide, it will help you figure out what is going on

https://www.2carpros.com/articles/car-heater-not-working

First feel the heater core hoses with the vehicle hot. They should be hot. Tell me what you find.

Really sounds to me like your blend door is not working in your car and is stuck in the middle of the temp range.

Check for clogged-up heater hose and the heater core-could be the heater control valve. Coolant level is up to the full mark?

Did you check both your heater core hoses to see if they are hot when engine is up to temp?

Check the thermostat if it stcuk open and the heater core if its clogged-up, if it has an heater control valve check that too-if all okay-could be door problems, vacuum/actuators and HVAC control module.

Feel the heater hoses near the firewall, after your rig is at operating temperature. If they are as hot as your upper radiator hose, the thermostat is probably not the problem!

Observations? Other observations?

I do not know your rig well

I will try to help you

I'm still here!

The medic

Are they uncomfortably too hot to hold in your hand very long (all mentioned, after you reach operating temp). Or cooler after it idles a while, and really hotter just after a drive (if you check it quickly after the drive)

Does your temp gauge fluctuate from "higher" while driving to lower while "idling"

You can respond below at "add a reply"

The medic

By the way---i do not know you, so I am not directing this to be mean!

I do this to everybody, who is not "me"!

Did you install the thermostat prior to having this issue or after--even so, is it sitting with the spring down and pointy side up,
Have you had the heater hoses off and maybe misrouted them?

Really good one---are you full of radiator juice?

Is there any sort of "water switch" on the heater hoses---between one end of them, to the other. If there is, maybe its stuck partially shut. It might can be completely removed (now that it's winter time) and the hose replaced in full length or just the valve be replaced with a suitable coupler till you can do better!

Are they old and squishy, and maybe the water-pump is sucking the return flat?

Are there any kinks in the heater hoses?

I'm about to hit the hay--see you in the morn!

I will leave you with some thing to try

Take loose the highest heater hose on the engine--at same time watch the water in your radiator--is it falling as if you just bled the air from an air pocket?

If no results there, continue with this:

Connect a long heater hose from the water pump to the fitting in the engine (completely by-passing the heater core)how hot does this line get?

While that is loose, force water thru the heater core with a water hose---is it flowing freely from the open side?

Heck, if the water hose is connected to every heater hose in the system, (one component at a time) does it come out the opening on the other end of each component

Night--night

That oughtta keep you up all night!

The medic

Sorry, between my 1st and 2nd answer, "damonre" sent me a message, we were discussing the heater hoses and the radiator upper hoses' temperature!

The medic

Ok I would check to see why it using coolant. I would call around and find a shop that can do a chemical test on the radiator to see if it has a blown head gasket this will answer this with no guess work. Now as for the heater these systems are very hard to get full or burp the bubbles out so you may need more coolant you will have to check if all this checks out then get back to me and we will dig deeper into the heater system to see if the heater control valve may be bad. Thanks and Merry Christmas.