Hey guys

I recently picked up a 95 civic DX. It runs great but, I'm having an issue with the heater.

It only blows out luke-warm air, not hot.

Things I've done:

Adjusted heater valve cable
New thermostat
New coolant
Bled coolant

Both the inlet and outlet hoses on the heater core are hot.

What else should I try??

 

Heater core replacement, could be clogged up and reducing it's ability to radiate heat.

Thermostat that opens at a higher temp.

 

When you bled your coolant, did you have the heat on full hot? It's possible that it's clogged, but it doesn't hurt to triple check easier things first.

Also, I'm a bit disappointed that some unknown mod is shitposting in tech.

 

The inlet and outlet on the heater core are hot, so I'm pretty sure there's no blockage. But, I'll try flushing it to see if it helps.

Brand new OEM thermostat, I just installed it. Seems to be working properly.


Someone suggested I check the blend door or something like that, where is that located??

 

Blend doors are a commonly failed component when your heat stops working, maybe not on civic though.

Even if its not totally blocked up, if there's partial clogs it'l still stop the heater core from working well.

 

The blend door is the little box that the cable is attached to on your firewall. It's the valve that controls if coolant is getting to go through the heater core.

 

Check the bottom of the flapper box (heater core box)(blend door box).

There is a 4 way sliding switches setup on the bottom. On mine, on of the posts snapped on one of the flappers and when I slid it to cold during summer it naturally pushed the flap over the core. Then come next winter, I got nothing but cold air. Once I looked under the box, I noticed the missing piece and was able to turn the broken post with my fingers which gave me heat again.

You can see the section I am talking about from the passenger foot well close to the center console area.

See if you notice anything missing on the bottom of the box.

The part I am talking about looks like this and has white slider pieces that are dimly illustrated in the pic:



And you find this part on the bottom of the flapper box which resides behind the center of the dashboard and lower console but can be partly seen from the passenger foot well:



With mine, one of the white slider pieces was missing.

 

lol

When I saw his response to my question, I had to make sure I didn't mistakenly post in GDD... Since that's typically the type of BS response received when asking a tech question there.

Anyway, thanks to those of you who've offered helpful suggestions.

 

This is great! I'll look into this and see if I notice anything not functioning properly. Thanks!

 

Actually, you originally did mistakenly post this thread in GDD. A GDD mod moved your thread here.

Thread cleaned up.