First year I owned vehicle, I noticed that during the winter the temperature gauge would not get above 1/4. The heater was relatively cool, but my commute was relatively short so I downplayed the matter thinking the heater sucked because it was a fuel efficient car. I mentioned the problem when I took the vehicle in for another problem and was told that it was in fact normal.

A couple years later I had a different job and my commute was now an hour long on the interstate. The vehicle would never warm up correctly. I would leave work at night with the temperature at -10f and arrive home an hour later and would be freezing. I could see my breathe.

I resorted to taking a blanket with me, and having aftermarket seat heaters installed. I called the dealership and wanted to get the thermostat replaced, coolant changed, whatever I could get done so the car would be warmer. Found out that there was a update available to the instrument cluster. They updated the cluster, and driving home from the dealership the temperature gauge was at the halfway mark. I had heat in cold weather.

A couple months later I started getting check engine codes for thermostat regulating not up to temp, or something similar. The dealership replaced the thermostat, and the code went away for a couple weeks, then came back. The code now persists in the cold winter months and goes away in the spring. I'm fortunate to have heat so I really don't care about the CEL.

First cold day of the year since owning my Elantra and there's no heat when you come to a stop at red lights or in parking lots. Took it in for service and they said "oh yeah there's a tsb on that" Re flashed an update to the computer. Next day the same thing is still happening.

Took it in the very next day, same complaint. Was told this time that the Elantra, to save fuel, has a smaller pulley on the water pump so at low rpm's the water pump is barely pumping, I guess. This causes the heat to stop blowing hot when you stop. If this is true Hyundai needs to come up with a fix. This is unacceptable when it gets anywhere under 30 degrees out.

Update from Jan 30, 2020: The heat still does not blow when stopped. Made another appt at the dealer and was told many people have complained about the issue but Hyundai has no fix yet, they did issue a tsb. So I called Hyundai America and complained. They told me there's nothing they can do, but they hope a fix might be found and if so then a recall would be issued. So I think this is the last Hynudai I will be buying. They do not even care that its winter here and I have not heat to defrost or anytime I stop for more than 5 seconds.

I bought the car brand new in the spring and didn't need the heat. I live in Minnesota so, heat is critical. When I tried the heat in October 2017 it takes 20 mins on a freeway to get decent heat. Forget getting any going on local errands. Brought to the dealer multiple times they say it is registering correctly. Gave me a Sante Fe loaner and that had great heat, so they can make a vehicle with great heat but this isn't one of them. When you come to a stop at a light the blower reduces the amount of air coming out. Would never have bought knowing the heat problem. I won't ever buy a Hyundai again.

This car has no heat issues since new. When outside air temps drop below 20 deg F there is little to no heat, even after driving 15 miles at highway speeds. I have been to the dealer 3 times, 2 thermostats, one self-replaced as I am a retired as a master tech and felt it was stuck open and making a false reading to the PCM. The computer was re-flashed. It comes down to not being able to repeat issue, or no problem found by the dealer. Other than a tech making a false statement that I had a mouse nest on the cabin air filter blocking air flow, which was a out right lie, esp since i had just personally changed the filter the day before the last trip to the dealer.

The manufacturer knows of this problem yet offers NO help in the way of a perm, repair.

I leased my only car, a 2017 Hyundai Elantra brand new with 9 miles on it. After I had owned the car only three days, with 173 miles the heat stopped working. The dealer put in a new thermostat and the car had heat for the next 3k miles. Since then the car has had poor heat. Finally, the car just stopped producing any heat. The dealer has tried repairing the car and even put in another thermostat. The dealer was unable to fix the problem so a Hyundai Corporate representative covering the Northeast area of the US came up and was able to recreate the problem. The computer in my car was updated and I was told my car now had heat. When I went to get my car at the dealer it had no heat to defrost the windshield. Therefore, I have been unable to test drive the car to see if it has heat while driving. The car takes a half hour of idling to warm up the engine halfway and even then the car doesn't have any heat to defrost the windshield. I live in Maine and can't get enough heat in my car to defrost the windshield to see to drive my car. Hyundai Corporate says the heat has been tested and is operational. Therefore, they refuse to do anything else about my heat and won't let me out of my lease.

Didn't know about this issue until way after i bought the car since inter wasnt very bad last year and i barely noticed. This year with the temps getting close and into the negatives the car would struggle to come up to temp and heat would not work. Took the car tot he dealership on 1/31/2019 and they replaced the thermostat. the service person said there was another car with the exact same problem. When I picked up the car after work, the heat worked great, as it was ale in the teens for the temperature. But this morning 2/1/2019 the car struggled to stay up to temp, but it was at least blowing lukewarm air on the highest temp setting and the highest fan speed. When I got to work and put the car into park, the vents started to blow out cool air again while it was idling and fully up to temp at this point.

In Jan 2018, after still having issues with my car, I returned it to the dealership, they had it until the middle of Feb. They spoke with Corp, and were advised that this was a known issue with this model and offered suggestions. I spoke with the service department almost daily, they gave me a loaner, and advised me of the status.

The southeastern engineer came out and checked my car, gave suggestions and tried to help fix the issue. I was suggested to file a claim with Corp, which I did. Mid Feb I went to "test" my car since the loaner needed to be serviced and returned my car 2 hours later because the issue was not fixed. The claim with Corp was closed, but the car was not fixed. When I returned to the dealership that afternoon and we all felt the cold air, and the suggestion was to have the Southeastern Engineer with Corp come back and I would bring the car back then.

A few days later I called the dealership to get the scheduled appointment, and that was set for Feb 26th. See next issue

in Oct (2017) I noticed the heat works until the car comes to a complete stop when stopped the car blows cold air. I took it to a dealership and they changed the thermostat.

The problem persisted, The mileage was over the GA lemon law but inside the 100,000-mile warranty. All covered, and the dealership was great

Update from Mar 30, 2018: On Dec 11th, 2017 I took my car into the shop, after noticing that the heat only works when the car is moving. When you stop, the car blows cold air. The dealership changed the thermostat and said that it was good.

The heater functions very poorly in this car. I didn't notice the heat issue until the temperatures began to get below 50 or so. As the temperatures dip below 50 degrees, the engine takes noticeably takes longer and longer to come to normal operating temperate. At around 32 degrees it takes about 15 to 20 minutes to warm up at highway speeds. In the 20's it takes a good half hour, and if it's in the single teens of single numbers, it never really warms up. The temperature gauge will rise as you accelerate and fall when you coast down hill. It will also fall if you turn the blower up. The dealer has worked on it 2 times so far and agrees that it is producing inadequate heat, but says that Hyundai has no fix and recommended that I call them directly and complain. They told me that they have had about 35 customers complain about the issue.

This 2017 Hyundai Elantra had a factory recall (I never was notified) for thermostat replacement. It does not produce heat. I have been back and forth to dealership, they finally gave me a loaner and my car sits on their lot until Korea has a resolve for this. This car does not produce any heat when I start it up and let it run for 10 minutes. Temp gauge does not move from below C. After I drive for about 30-40 minutes at Highway speed (110 km/hr) the temp gauge comes up to almost half, but car is cold, widows hard to keep frost free, feet freezing.

When I phoned Hyundai customer service Canada and they told me there was no problem with this car. I believe this car was developed for a very warm climate! I’m Winnipeg Manitoba Canada, the temps have been around -35 to -40C. I expect a new car to produce heat if it is sold in this part of North America. I feel the dealership will call me end of February to pick up my car because it will be starting to warm up.

Update from Apr 10, 2018: I filed a claim with CAMVAP against Hyndai

I do have video's and pics..( i will upload later when my have my cord available to plug into the computer) I have the same issue as other owner's of this NEW Elantra 2017. No heat it has been in and out of the shop like 4 times now. Including last year! They put a new thermostat in it thinking that was the problem..ehh..nope... brought the car back to them...they gave me a loaner ..finally after borrowing from family because they didn't have any loaner's..BS! Than they give me another loaner..WITH THE SAME PROBLEM! NO HEAT! The guy that lend me this loaner car said .."yea i have been fighting with head quarters about that car not having heat but nobody is listening. BUT you will let me take this loaner..knowing its like -24 degree's in upstate new york?. what is wrong with these people?! But anyways needless to say they have tried everything getting the air out of where ever, new thermostat, driving it duplicating it..they have no idea what is wrong it!. I am NOT taking this car back unless it is fixed! Again i have pictures and video's i will upload later! I will keep posting updates as the ball starts rolling. Oh by the way..it is being investigated..all of it the loaner, and my car... :)

Dealer tried telling a retired ASE Gold Master Tech there was air in the system. I gave them the tsb number TLL right from the Hyundai owners web site. Still there is poor heat and the motor takes about 20 miles of driving to heat up, when it should be 2 or 3 at highway speeds.

It is a pity to take it to a dealer who wants the car left to do an under 1 hour repair.

Update from May 27, 2017: there is a recall/TSB for this issue the number is TLL, the early thermostats used were also bad.

I now have heat and a return of 32mpg's

I am having the same problem after only 500 miles and owning the car two weeks. How pathetic this could happen in a short period of time. Also, the rear truck that is supposed to open if your standing in front of it is not working either.

Probably no solution to that problem either. I read on-line that Hyundai has had so many complaints with their cars and they could care less about the customer! Will never buy a Hyundai again and I will advise anyone thinking of owning one to buy a different brand.

Brought a 2017 Hyundai Limited car new with 53 miles on it on a warm winter day and drove it that day. Several days later, drove it when it was 0 degree's out, darn cold and could NOT get heat from the heater and noticed the engine thermostat was on C (cold). Took it back to the dealer at 123 miles. Wife took me home. Dealer called the next day said it had air in the line, they cleared it out, service mgr drove it & said it was OK now. Took it home & back to the dealer right away with 133 miles on it with SAME problem.. They acknowledged some 2017 Elantra's had this issue. They gave me a 2017 Elantra Limited to use. Drove it home, five miles and took it back to the dealer with the SAME issue. They gave me a Sonata Limited to use untill they fixed mine Elantra. It's been one week and with no fix. They said they had a Hyundai factory tech test it and said it met their specs which to me doesn't make sense. Now they're going to have a Hyundai Factory Engineer review it. No solution at this time.

I asked why dealers are selling them with a known problem. Answer was there's NO sales stop order or recall from Hyundai. So it's BUYER BEWARE. Unless your in a cold climate, you may not notice this issue other than the gas mileage is low due to the engine never getting hot enough to operate at peak efficiency. So it's also a low gas mileage issue (MPG) since the engine thermostat stays on the C. Dealer say's it's a computer software problem and are waiting for a fix on the Elantra's.

Update from Jan 16, 2017: This is an ENGINE problem because the engine thermostat isn't functioning correctly, not an A/C, Heater as I previously stated.

Dealer called me 1/16 after they had the car over a week and said they have no solution. I was told my choice was to pick-up the car and drive it as is until they have a solution or call Hyundai of America and file a complaint which I did. They assigned a case number to my complaint and said they would get back to me in 3-5 business days

Update from Feb 28, 2017: After 45 days at the Hyundai dealer's garage, three thermostats, 1 water pump and 5 purges to the water cooling system, the engine is giving heat to the cabin and the dash thermostat registers as the engine warms up. I was told the last thermostat and purge of air out of the cooling system solved the problem. Remember, the thermostat is now electronic and is computer software managed, no more mechanical thermostat. I'd give the factory a "0" for their ability to solve this in a timely manner. Since it took over 30 days to solve Hyundai agreed to giving us compensation for this problem since my wife likes the car.

At this point we believe the problem has probably been resolved.