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nguyenb73 05-16-2007 07:56 AM

AC blowing out hot air
Please help. We have a Tempstar central ac unit. It was working fine until last weekend. It blows out hot air. The fan and the outside unit seem working fine. Anyone know what is wrong with it? Could it be that it ran out of freon? If it is, how should I check for it? Any helps is greatly appreciated. Thank you so much.

glennjanie 05-16-2007 09:05 AM

Welcome NGuyENB:
Here are some things you can check with out too much trouble:
Is the thermostat set on "cool"?
Are the lines from the outside unit intact?
From the outside unit, does the small line feel warm and the large one feel cool?
Take the caps off the lines near each end, or one end.
Under the cap is a valve stem just like in a tire; press one of them just briefly, to see if there is any pressure at all in the systme.
Turn off the power and take off the top of the outside unit. Look down in the outside unit and see if you can see through the outdoor coil. If not, it needs to be cleaned. Dirt and grass clippings will make the unit heat up even though it has a full charge of refrigerant gas.
When I sold that equipment we had a saying, "Clean first, gas last".
Occasionally the "A" coil inside will get dirty also, same result.
Remember the gas doesn't burn up or consume it can only leak out; so, if yours is low on refrigerant, there is a leak somewhere. Adding refrigerant to a dirty system will improve it for a short time but the systme is overcharged and in danger. That's why amature technicians will say, "It just needed a little gas." Now your money is gone and you still have a problem.
Please post back and let us know how it turns out.

nguyenb73 05-17-2007 11:44 AM

Thank you Glenn for the quick reply. I will check on those stuff today.

nguyenb73 05-21-2007 02:55 PM

Hi Glenn,

I did everything. The thermostate sat to cool, the lines of the outside unit are in all intact. The small line feel warm and but large one feel like room tempeature. There is pressure under the valve with stem, I cleaned out all the spider web, bugs and even bees inside too. But one thing I notice is the compressure. When I turn it on, the fan runs, but the compressure doesn't sound like it kicking in. It sounds dead. I think it needs to be replace. What do you think? Also, the unit we have is old, June 1990. Is it make sense to replace the compressure or should we replace the whole unit? Also, do you have any price range I can aware of for both replacing the compressure and for replace the whole unit.

Thank you,

glennjanie 05-21-2007 04:32 PM

Price range: 1,200 to replace the compressor, just under 3,000 for whole new system.

Before we spend a bunch of money though, we need to check some other things:
1. Remove the access panel outside, locate the contactor, with your screwdriver on the plastic part in the middle, push the contactor in to see if the compressor runs.
2. look in the access panel for burned off wires, turn the power off, pop the junction box cover off the compressor, look for burned wires again.
3. Disconnect all three wires from the compressor, use an ohmmeter from each of the three terminals to ground. Record the reading on each one; two of the readings added together should equal the third reading. If this won't add up the compressor is shorted out and needs to be replaced.
4. The unit is past its economic life (12years) and should be replaced, indoor and out.
5. In my experience, about 8 out of 10 a/c repairs are simply a burned off wire. I hope you find one burned off and can reconnect it for another 5 years of running.

nguyenb73 05-22-2007 09:01 AM

Hi Glenn;

If changing the whole new system, what need to be change from the inside unit? I am thinking of changing the whole system since it is pretty old and we do using it alot in the summer for the kids. It does get very hot in Sounthern California in the summer, when the kids are out of school. We are bout to call someone to come and take a look. Do you have anyone in Orange County that you recomment?

Thank you,


glennjanie 05-22-2007 10:33 AM

Sorry Bien, I don't know anyone in CA. The best I can recommend is to look in the yellow pages for a dealer who handles Janitrol or Goodman products. They are amazing copies of the Tempstar line and cost a lot less, with the same warranty or better.
The reason I said to change the inside unit too is to get an "A" coil that matches the condenser unit and the new air handler may have a variable speed motor as opposed to the fixed speeds of yesteryear.
I really hope you can find a burned off wire and replace it. That would cost pennies.

CraigFL 05-22-2007 12:28 PM

It will be expensive to replace the complete unit since the govt standard is now 13SEER minimum. This will mean probably extensive replacement of parts including the inside coil which will probably become larger requiring ductwork modifications. You might find it easier on the wallet to just replace the compressor if that's the problem. It could be just low freon protecting the compressor from turing on. It's time to find a technician to help you with this. If you want to find a good shop, you might try searing the Better Business Bureau website ( It will certainly rule out some of the not so good places...

nguyenb73 05-22-2007 01:03 PM

Thank you Glenn and Craig. I learned more about AC the past few days then the past 33 years. I will keep you updated to what we are going to do. Thanks again for all your help.


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