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Not much heat from heater (1/13)
 4/13/18 5:33pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

My '75 does not put out much heat from the heater.  It seems that the cars from the 50's and 60's could roast you out of the car with the heat on full blast -- mine does not.

I flushed the heater core and water flowed freely through it.  The fan works fine on all 3 speeds.  I put in a new thermostat (165 degree, I believe).

(I had added a valve in the heater hose, which is turned on full.)

One other note, this was an A/C car, but the A/C had been removed.

Any ideas on why I don't get much heat?  Do most Vette heaters put out enough hot air?



|UPDATED|4/13/2018 2:33:21 PM (AZT)|/UPDATED|


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Re: Not much heat from heater (2/13)
 4/13/18 6:55pm
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 554

Did you visually verify that the heater valve is open internally? Is it a problem that the air coming out is not hot enough or the air is hot but there's not enough quantity? I drove mine to work daily and in the winter time the heater put out plenty of hot air.

|UPDATED|4/13/2018 3:55:31 PM (AZT)|/UPDATED|


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1973 L-82 4 spd

Re: Not much heat from heater (3/13)
 4/13/18 10:10pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

73shark said: Did you visually verify that the heater valve is open internally? Is it a problem that the air coming out is not hot enough or the air is hot but there's not enough quantity? I drove mine to work daily and in the winter time the heater put out plenty of hot air.



Yes, the heater valve that I put in is a ball type made for a heater hose.
I seem to get good air flow (it seems anyway), but it is not very hot.



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Re: Not much heat from heater (4/13)
 4/13/18 10:58pm
73shark
Standard Member
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 554

Try checking the temperature of the hose going in and the hose going out and see if there's any big difference. You can get one of those inexpensive laser temperature guns at Harbor Freight if you don't have one. I assume that the hoses are free and clear.

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1973 L-82 4 spd

Re: Not much heat from heater (5/13)
 4/16/18 5:11pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

73shark said: Try checking the temperature of the hose going in and the hose going out and see if there's any big difference. You can get one of those inexpensive laser temperature guns at Harbor Freight if you don't have one. I assume that the hoses are free and clear.

I bought a laser temp gun:  The temperature difference between the inlet and outlet heater hoses is about 10 degrees with the heater fan on high.

Checking the temp at the heater air outlet at the passenger side is about 130 degrees (anyone know if this is about right?)  The driver's side is about ten degrees cooler.

How much trouble is it to pull the heater core?



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Re: Not much heat from heater (6/13)
 4/16/18 9:49pm
F4Gary
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Grapevine, TX - USA

Vette(s):
1972 LT-1 convertible with factory air.


Joined: 8/26/2006
Posts: 964

That is certainly hot enough to heat the cabin.

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Re: Not much heat from heater (7/13)
 4/16/18 10:41pm
73shark
Standard Member
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 554

As one that installed factory A/C in mine, I'll say it's medium difficulty.  IIRC, you have to do it from the inside.

What was the temp. of inlet hose? 

If 130* air is heating the interior, then maybe you're not getting enuf air flow.

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1973 L-82 4 spd

Re: Not much heat from heater (8/13)
 4/18/18 8:16pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 163

73shark said: As one that installed factory A/C in mine, I'll say it's medium difficulty.  IIRC, you have to do it from the inside.

What was the temp. of inlet hose? 

If 130* air is heating the interior, then maybe you're not getting enuf air flow.

I wonder if when they removed the A/C (assuming they did go inside it -- it looks like the fittings are still jutting out of the housing) they did something to disrupt the airflow in the heater box.




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Re: Not much heat from heater (9/13)
 4/18/18 8:48pm
73shark
Standard Member
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 554

If the evaporator is still in the housing, then perhaps it's clogged w/ debris, mold, and/or mildew.  You can open the housing up w/o removing the engine and check the evaporator.  Not sure why they would've disabled the A/C.  Ermm

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1973 L-82 4 spd

Re: Not much heat from heater (10/13)
 4/24/18 11:22am
danascar
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Germansville, PA - USA

Vette(s):
1974 Coupe 358ci 4 speed Black w/Medium Saddle interior w/79 custom leather seats. . 1999 Covertible, 6 speed, Atomic orange, Oak interior


Joined: 1/28/2010
Posts: 803

As long as you don't have a run hot problem you might want to change to a 195 degree t-stat. 165 is on the cool side.  

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Dan T