I remember seeing valves on the hoses to the heater that people had installed to prevent this problem

 

Throttling the heater core in today's car can/will have adverse effects on engine cooling. The heater core is most often an active part of the coolant loop and needs to be there or taken out w/ hoses coupled for flow.

 

Yes, you were the guy that blew me away by telling me how these new fangled systems work... The heat is an annoying problem when the temperature is even down in the 60s and horrible when it is 50 degrees higher and working against the A/C.

 

I have been thinking and wonder if using some heat reflecting tape on the door that separates the heater core from the A/C evaporator would work to solve the problem.. The DEI Gold stuff or aluminum foil covered adhesive foam or combo of both maybe... C'mon KC tell me whatcha think..

 

It's against my logic that the heater core is mounted inside the cabin, buried in the dash, and always running hot. But it is...

Containing the heat in the heater box is what the air mix door is all about. Seeing how getting to it is a royal PIA there's not much I can see doing without pulling the whole thing. I doubt the heater box is insulated in any way.

There's probably some sort of a valve that could be installed to effectively isolate the heater core and maintain coolant flow. Some current [German would be my guess] vehicles might very well utilize it.

I use the AC on a regular basis, year round. Just yesterday I took a close 'feel' of the vent temps [w/out AC] based on concerns raised in this thread. My FIT is running normal. I'll check the cabin filter to be sure it's clean and free flowing.

Beyond that I would say - if it's too warm in the cabin open a window or turn on the AC or both.
I learned the joys of cruising w/ the heater on and all the windows open years ago [then the joy of doing it w/ AC once I owned a car that had it].

Today it ain't so politically correct - so what! All this economy concern can become a dead-end obsession after a while and lead to sleepless nights to a yearning for things to be logically simple again.

I know where I can pick up a good 62VW for under 5K - but truthfully I'm not going to touch it. Then again I saw a 1924 Dodge Tourer [fully restored] a few weeks back. That car actually has manual variable speed timing mounted on the column and a cabin framed in wood and steel fenders you could sleep on. For six figures I could pick that jewel up - NOT!

 

KC... That is a wonderful post that deserves a rep. I tried but will have to throw some more out elsewhere and come back.... I had a beat all to hell 62 Beetle I paid $ 250 for and used as a loaner to customers... We wore the engine completely out with out breaking anything or dropping a valve.... To get it started in the end required one person at the start switch and another to pull a couple of spark plug cables off of the plugs and hold them just a smidgen away as the starter was turned to arc the spark to them and then do the same to the other 2. Once it was going all was fine as long as it wasn't shut down long enough to cool down... I'm all for rerouting the hose around the heater but what you said about it being part of the cooling system is a little scary when I think of how hot it gets here in the summer..Using water wetter in the cooling system and removing the cabin filter helped cool things down some though and may have lowered the temperature enough that bypassing the heater during the hot months would be feasible ... When the ambient temperature is cool enough to need the heater, the water temp is right at 170 degrees with water wetter.

 

I went back to the dealer a few months ago and they told me that warm air through the vents was normal. I started researching this on the web and looks like this is common to quite a few Honda models. One post which resolved the problem for a Honda Odyssey indicates that the cable was not closing the heater control valve completely and tweaking the cable resolved the problem.

Does anyone know if the Honda Fit has a heater control valve? If yes, where is it located? I'm curious to see if this is completely closed when I have the rotary know turned all the way to blue. Also, if I tweak the cable so that the heater control value is closed fully am I risking any damage to the car? I'm assume that Honda deliberately designed the cable not to close the valve 100%.

Any thoughts?

 

Sorry to bump such an old thread but this has been something that has driven me crazy since I bought the car. While I was changing the cabin air filter I had a pretty clear view of the door that opens and closes with the fresh air/recirc lever. That door has a rubber flap built in to it that doesn't seem to seal very well. Is that rubber flap needed? I was thinking this could be where the warmer air is getting back in to the system.

 

I think it's a pressure relief flap so when you slam the door it doesn't break the flapper (or at least flap it around). I wondered the same thing and this is the only explanation I could think of, maybe someone else has a better one. I wouldn't seal it, Honda engineers put it there for a reason.

I don't think this would affect temperature either way, much.

 

Thanks for bumping I posted similar problem a couple of years ago and couldn't get the answer, researched and found heater is used to dry the a/c air. but doesn't adderess the no a/c or heat time when you would like to have fresh air coming in vent.
A/C here in Florida is marginal and needs all the help it can get and having heated air to cool when at high temps doesn't make sense, even if it is humid cool air it will be better than not enough cool.