HVAC blows warm air

10 years ago

Greatings everyone,
Long time user of Gardenweb, but this is my first post in the HVAC forum. My central AC was put In just under 5 years ago... I have an all electric home with a heat pump. The heat worked fine this past winter, but I am trying to run my AC and I think I'm having some issues. The past 4 years my AC would kick on for 10 minutes to cool the place, then kick off for 30-45 minutes, then back on for 10. This cycle would continue just running at 10-15 minute intervals.

This year I've had my AC on for about 2 hours straight and it's failed to kick off and is keeping the temp at 74. When it kicks on initially, it'll blow just neutral air (neither warm or cold). After 15 minutes of that, it'll blow very cold air. Then another 15 minutes will pass it'll blow the neutral air again. This cycle continues keeping it at 74. I did go outside and I noticed when it blows the neutral air, the fan stops running. You can put your hand over the outside unit and feel the heat coming off.

I have two brass lines running from the outside unit to the inside. The larger pipe (maybe 1") is very cold. The smaller pipe (maybe 1/4") is warm/hot.

What are your thoughts on this? Is it something that I can fix or should I hire it out? Either way, the biggest question is a guess on the price to fix.

Thanks!

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Comments (9)

Servicetech
10 years ago
Does the outdoor unit shut off completely when the fan goes off? May just need a condenser motor or even just a cap.
ricksample
Original Author
10 years ago
Everything else outside sounds like it's running... the unit doesn't shut off. When it's blowing the warm air and the fan stops, the unit makes a loud buzzing sound and you can feel it putting off hot heat. As soon as the fan starts back up the sound goes away and it pushes out cold air.

I haven't taken anything apart on the outdoor unit yet. But I took the panel off the indoor unit and it looks like new on the inside. I'll look at the outdoor unit more in depth tomorrow.

Are those two things something that I can replace and if so, how can I tell which part may be bad?
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In technical terms I can only explain it if you understand how a refrigeration cycle works. In simple terms air conditioning cools a room by removing heat from the room and releasing it outdoors. Go to your outside unit while it's cooling and you will see that hot air is coming from it. You will notice the same hot air on the outdoor portion of window units. Doing as you propose doesn't transfer the heat outdoors. Making matters worse,the heat generated by the portable's motor is added to indoor air. If you are willing to tolerate some Rube Goldberg contraption,have someone run a flexible hose from a large fan on stair landing up stairwell to 3rd floor. That will transfer cold air from lower floor to upper floor. As I already said,a tech that know's what he's doing can make your system cool all rooms. One can only tell what's wrong after examining the system but it could be simple as a duct which has come loose. Does all your neighbors have the same problem?
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ricksample
Original Author
10 years ago
Just an update... I took the cover off the outside unit and the capacitor looks normal... it isn't rounded on top.

Also, I ran the AC this morning for around 40 minutes. It brought the temp from 72 down to 69, then the fan stopped and it made the loud buzzing sound. With this buzzing sound this time, it was making a loud whistling sound. Kind of like when you let air out of a full air compressor. I think this is normal, but it sounded worse since it was also buzzing.

From what I'm reading online, it looks like it may be the copacitor or the fan motor.
energy_rater_la
10 years ago
warranty still in effect??

best of luck.
rickymartin85
10 years ago
Possibly unit could be overheating from a dirty condenser (outdoor unit coil) coil.Turn the power off and clean with a garden hose.
ricksample
Original Author
10 years ago
Ok I called a repair company and they said the fan motor was bad. I gave them the ok and they said they could replace the fan motor & capacitor for $224 + 65 service charge. Total $289.

However, he gave us a number to call to see if we can get it covered under warranty. He put the unit in on 5-7-2008 with a 5 year warranty. Today we are 2 weeks past warranty. However, the house was built new and we didn't get to move and use the unit until 6-19-2008. So maybe we can get some free parts and maybe not... who knows. But the price doesn't sound to bad.
ricksample
Original Author
10 years ago
Update: It looks like they will cover the cost of the motor under replacement even though it's two weeks past warranty. It looks like the total bill could go down to around $150 and that includes the capacitor, motor, labor, service call. which isn't bad at all. Just letting everyone know incase they come across a similar warranty issue.

Thanks Everyone!
thegrumo
10 years ago
Hi ricksample,

Did changing the fan motor solve the problem? I'm having the EXACTLY the same problem with my AC for the past month. However, the fan motor on my unit seems to be working fine. Was your old motor 'seemed' to be working well before you called the servicemen?
klem1
10 years ago
grumo,I suggest calling a repairman NOW,1 month's worth of that can burn out the compressor,make a mess in coils and lines that can cost as much as a complete system replacement.

HVAC blows warm air

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HVAC blows warm air

Comments (9)

Servicetech

ricksampleOriginal Author

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ricksampleOriginal Author

energy_rater_la

rickymartin85

ricksampleOriginal Author

ricksampleOriginal Author

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klem1

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ricksample
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