Why is my heater not working well in my Honda civic

I think the air duct to the heater core is not adjusted correctly.

Hi.. I think the engine is broken head gasket

so many options for fault...lol there are many things to try...first have you ever had a problem over heating? has the car ever over heated (if you let it sit in park and idle for 20 or so minutes) to determine if it is a water pump or head gasket...be sure to check all your fluids. a way to see if the heater core is leaking, is to (on the passenger side of the car pull up the carpet, i mean even the insulated black mat, and feel with your hand for moisture, or water, if it is wet, then the core is leaking..i can talk you through how to check if it is clogged, how competent are your mechanical skills? it can be as simple as the actuator door being stuck, so relax and dont stress too early....let me know if i can help more.

You can have the heater core back flushed also to improve the flow through it.

If your car isn't overheating or losing radiator fluid, have the mechanic check the thermostat. If it is stuck open your heater will not work properly. You may have gotten a bad one that didn't last long.

First check your engine coolant, it might be low. If the coolant level is ok then you may have a vacuum leak in heating controls. The heating system uses vacuum pressure to move the heat control valve. The higher the engine rpm the more vacuum the engine produces. This could explain why the heater seems to work when going over 30 mph. If your car heater blows cold air and your engine temperature is at normal operating temperature the problem can not be a thermostat or a bad head gasket. Good luck.

I just needed to replace the thermostat. I had done that once but I guess I put in a bad one and it stopped working very quickly. My most recent one has lasted well over a year and my car is doing very well.

Hi guys ...Cars heating system and car radiator cooling system are same thing but performs different operations ..first the heat which is generated under your car engine is carried off by the coolant while the water pump ..works to circulate it over the radiator and at the hose neck usually there are two sensors one to detect if your coolant is hot enough so that it can kick the fans ON ,the other were it gives your car a signal to lower the RPM when u r car calms down specially in the morning under cold start when its heated enough and the rpm drops ... 1000 rpm this how the heating system of your car's operatesto control temp so that u r engine block does not break open cuz of access heat within .. Now when you turn ON heat on a cold morning it takes a while to heat your car needs to warm up and using engine heat the coolant in your car heats up and when u turn on u r heat vent now the coolant which is hot rather flowing straight to your radiator where it cool's down ..would flow through u r heater core under your cars dash board and goes to radiator and that's how u get the hot air ..hope this helps !! Mustafa!!

heater core

With mine, it was a blown head gasket. Hondas can be very subtle.

Check your thermostat sounds like its stuck open so your fluid is constantly flowing never fully warming

in frigid 10 degree air, can having too much water to Antifreez ratio cause, ok hot air on the interstate, then get off & first no hot air, then temp light goes up kinda quickly. i need to add some straight antifreeze right?. '01 civic

then temp guage goes up guickly

Hi there; sorry to jump in on this thread but I have an issue with my heater in my Honda Civic too. After a bad crash when a Tesco junneraut decided to drive into the side of us when driving a few years ago, the car was fixed (in retrospect I would say it was a write off ..) the heating aways made a noise when it was used (and air con). It used to make so much racket that I called the old insurer and told them they had not remedied the issues post crash and of course they denied it. I stumbled on with this racket when the car heating/cooling system was being used because a mechanic told me that it would be a massive deal to fix it because of the interior design of the car (which made sense as it is all built up and looks impossible to get behind/into) - and now the heating/air con has broken 100%.....I have now finally had time to do some research here and am reading the exact opposite of what the mechanic told me (who was doing my MOT at the time). It sounds as if this car/model has an Achilles' heel with the heating.....I am going to take it in tomorrow but any advice or more shared views much appreciated. Thank you. Anita

I HAVE A 09 HONDA CIVIC 2.2 CTDI WITH A LACK OF HEAT FROM THE BLOWERS IN COLD WEATHER I am having issues with the time it takes for the car to heat up. After conectiong my phone to the ECU I have found my civic will warm up from 10 to 50 Degrees C in 3 minutes as long as the revs are at 2000rmp or less. If I take the revs to 3000 the temperature can go from 70 to 50-40 in 30 seconds. I have changed the thermostat and checked levels etc. but I have not yet resolved the issue. This is a real pain as in winter temperatures I can drive for 25 mins before I get real heat from the blowers. It will help that I now know to keep the revs low in order to warm the car up where as last winter I was keeping the revs high to attempt to warm the car a bit quicker.

Buy a new 2017 Honda

Heater modulator actuary (heater door motoer under dash) - 4 #15 hexigon nut head/screws - remove old motor and replace. Remove Glove box with your hands and you'll see the white or black "motor" . Close vent near left passenger foot area. Before you start watch YouTube video. I haven't found it on here.

Oooops. Heater door modulator on my 1998 Honda Civic DX unlike my 2003 Saturn Ion. Please disregard my theoretical fix Flush out heater core, maybe.

hello guys....i would like to share my experience here.....Bensin or petrol cars hearters are always working quickly than diesel car heaters. One thumb rule is "heater always work good when car engine is fully warm". In extreme winter or in cold weather diesel engine always takes time to warm up as compare to bensin cars regardless you have new or very new car. but ofcourse newer cars are more efficient than olders ones......just calm down and use the way it is......

I have a 2017 Honda CRV and the car takes forever to warm up - brought it in to the dealer and it checked out normal - so normal heating in a Honda CrV sucks :)

I have a 2017 Crv with the same issue. The dealer says it’s because the engine size is too small for Canadian winters.....trade it on a Chevy Equinox!

Hello everyone. Maybe I can get someones help here sine I have tried almost everything to get my heat working. I have a 2012 Civic. when I turn on the heat I get cold air all the time. So this is what I have done so far. Replaced the Radiator, Replaced the Hear Core which was leaking, then still no heat. So I replaced the Thermostat , still no heat. Replaced the Water pump and flushed the system 4 times. Everything seems to be circulating just right. you can feel the return coming in hot and the fans kick on when the radiator senses it. Dont know where to go from here. Pretty much stuck. New blower was also just installed and still no heat at all. All i get is cold air. If anyone can help it would be mush appreciated. Thank you

I Have a 2016 Civic with the small turbo engine. Love the car, great fuel economy and great acceleration. Only problem, that little efficient turbo cannot produce enough heat for cold North Dakota winters. Okay on the highway, horrible around town. At low speeds and idling it won't heat adequately. Had it to the dealer twice, they are aware of the problem but Honda says it "meet specs."

I change thermostat and flush coolant everything work good now

Hi

you all need to make sure you run car until all air is out of system.park it slanted somewhat tilted away from radiator cap side of radiator.u know air bubbles rise to highest point fill your radiator and let it idle until you see 100 percent their is no air.they didn't put a bleeder on my 2003 and many more and that small bit of air can cause no heat at low idle but if you get heat when you drive and no overheating and operation temp is good then try this.hope it helps

Thank you Robert. I will try this once this crazy weather breaks. I don't have a garage so makes it pretty hard to do anything in this weather. Thank you again.

I have 2002 civic 1.7 and having heat and coolant issues as well I did all the simple stuff first. cooling system flush new rad cap new thermostat. And made sure coolant was filled with no air bubbles park on hill with rad as highest point and use non spillable funnel to fill squeeze all hoses to get air bubbles out and run car with cap off and circulate fluid through heater core with controls set to max heat. Onc coolant is circulating and no bubbles are coming install rad cap and fill coolant in reservoir to proper level and mark that level with marker. My car ran good and heat worked awesome for 4 days then same prob at idle after driving no heat drive again with rpms up and heat. Then noticed coolant in rad is down low and reservoir is overflowing.coolant is pushing out into reservoir and not returning to rad when cool so I refilled rad and changed cap again I also checked hose on reservoir for flow it was unrestricted. Coolant gets low in rad after 2 days driving so I pump coolant from reservoir back to rad periodically to refill rad and no problems with heat I can not figure out why fluid won't return to rad after engine cools even when you open rad cap you hear rad suck air in.....someone said if reservoir hose is flimsy it may be collapsing under suction cutting off return of fluid to rad so that is what I will change next !!! This is a mysterious phenomenon and seems like a widespread issue. Looks like some people didn't notice low coolant and overflow problem and end up overheating motor and blow head gasket and then think that was cause. I will repost my findings.

What did u find Guru? My car is having the same problem. Thanks.

I have found everyone who has a Honda civic has issues with the car not heating up from new to several years old, I changed the thermostats however after research I found the body of the engine take so long to heat up that the engin takes 30mins to get to a good operating temperature. Keeping the engine under load and keeping the revs as low as possable does help to heat the engine wicking however the car is very slow to heat. I have now chnaged to a ford and after 10 mins the car blowers are extremely hot.

yeah mine too , when i bought mine i noticed this - i assumed the seller removed the thermos. due to a headgasket issue , no lost fluid -no overheating - no mixed fluids , cant belive its the core , i do belive the comments about stuck doors though

Same problem, did the inexpensive things first, radiator cap, thermostat, kept overheating, bought Honda brand thermostat, flushed engine, changed radiator, refilled with proper antifreeze, burped the air out, runs like a charm. Several people and articles pushed toward head gasket, happy it wasn’t that.

You’re not alone. I have an 03 civic and I’ve had the same problem for about 4 years. Had an accident totaling the engine a few years before that and the mechanic forgot to put fluids in after they fixed it. The radiator over- heated after driving it for about an hour and trying to turn on the ac. and seems like it’s never been the same since with overheating issues from time to time. a few years after that, the heater gradually started acting and only blows cold air unless I’m going 30+ mph and even then doesn’t always work. It kills me because I live in the Bay Area where it’s a freezing 40 degrees half the time. Sorry for the wordy comment.