PDA

View Full Version : heater never blows hot



1988
09-19-2009, 11:58 AM
My accord's heater never seems to blow hot enough. When its freezing in the winter it will take about 15min before I get any heat. In my 92 accord it used to take about 5 min to warm up. The car has a new water pump and thermostat. What could cause this prob or are do these cars just take for ever to warm up?

charliekuney
09-19-2009, 12:42 PM
My car only takes but a minute or two to get hot. It's a problem with your car. :)

nswst8
09-19-2009, 01:47 PM
There is a valve at the heater core inlet on the fire wall check to make sure the lever is functioning.

If that is not the problem you have a clog, either in the core itself or one of your hoses. I had a clogged in a ford once, I should have checked the hose before tearing the dash apart.

1988
09-19-2009, 05:26 PM
last year all the hoses were replaced, the lever that controls the heat on the fire wall works fine. whats the easiest way to clean out the heater core?

mykwikcoupe
09-19-2009, 05:36 PM
remove the 2 hoses that enter the firewall. I like to remove them from the block. Hook up your garden hose to one of the hoses and see if you can run any water through it. Although not a good practice, after the water is verified to allow some movement I drain the heater core by allowing the hoses to point down. Then lift them as vertical as possible and top them off with drano or something. Since the heater core is copper and plastic the drano max gel works good. I was amazed at how much rust and gunk came out of mine. The previous owner tried that head gasket repare and all it did was contaminate the radiator and heater core passages. I allowed mine to sit 24 hours the 1st time and 48 the second. You cannot verify every passage is clean but you should be able to see an improvment in the water flow. Im sure the pressure from a full blast hose could damage the valve or the heater core so dont go pushing as much flow through it as possible.

This has worked great for me the past 3 times mine has clogged and each time the duration beween needing to do it almost doubles. Right afterwards Mine would blow hot air in 2-3 minutes and would actually get hot enough during the winter I couldnt use the full hot setting because it was too hot. Thats what i would do but thats just me. I rigged a hose end with a home depot garnen hose end and a worm drive fastener so I dont get wet and the hose just connects directly to it whwen I flush everything. Be sure to flush well after the draino.

nswst8
09-19-2009, 05:56 PM
Yeah if someone before you put in some radiator fix it solution, they could have used to much resulting in cogging the heater core. Best case you might be able to save it to some extent with the above suggestion.

1988
09-19-2009, 07:24 PM
Thanks everyone for the great ideas! mykwikcoupe thanks for the draino idea, i will give it.

1988
09-21-2009, 04:05 PM
Today I cleaned out the heater core and then ran drain through it, let it sit for 20min and repeated it. I then flushed the heater core out about a million times with water and hooked everything back up. The car seems to blow much hotter air. The real test will be tomorrow morning when its about 30 or 40 out.

nswst8
09-21-2009, 04:42 PM
Don't forget the nut warmers!

w261w261
09-21-2009, 04:48 PM
I've never had a problem with a clogged heater core, but I wonder about using Drano vs. a cooling system flush product. Aside from the instance of using too much head gasket repair junk, I would think that most heater cores get clogged because of rust-type stuff in the system, and for this a regular coolant flush would be the most effective. I would think that a Drano-type product would be designed for organic clogs - paper and human waste, and therefore would not be as effective. I know when you want to clean out a motorcycle gas tank that's rusted on the inside, you put in a solution of phosphoric acid (pool tile cleaner, "The Must for Rust," etc), let it sit for a day, then shake it with some marbles to get the rust off the sides. So that might work on a heater core too. What do you guys think?

mykwikcoupe
09-21-2009, 05:58 PM
there are a bunch of different ways. Ive used apple wine vinegar on rust and it works great. Ive used the radiator cleaners without much success personally. Most of my clogs are due to acid contaminates in the system itself. If you dont flush it often enough the bimetalic oxidation of disimilar metals causes a whitish sludge and is easily blown out with a hose except you cant control the flow of the water to go certain ways. You can remove the end tank and do iot that way which works good.

I tried the draino but i did have to do it twice. My problem is 100% the head gasket fix solution. I got a ton of red, orange nastyness. It was cheap and the highest potency stuff I could think of. i was more worried about it eating through something.

tyler125yz
09-21-2009, 11:35 PM
when my heater didnt work well in my s10 it was the head gasket....maybe check it out? I could be wrong though...

1988
11-03-2009, 05:44 PM
I did clean the heater core with drain like suggested and thoroughly rinsed out with water and the heater works better than ever. no more freezing driving experiences!

thanks for the draino idea mykwikcoupe

Ichiban
11-03-2009, 07:02 PM
I understand that calcium and other salts/metals in tap water cause huge mineral buildups in cooling systems. De-ionized water is cheap at Wal-mart or discount auto parts stores, and eliminates this problem.