Help! It's 86 degrees in the house and I have two kids and wife and the darn AC unit won't work.

Here's our situation.

We own an older sears Air Conditioning Condensing Unit (Model 867.816850) that sits outside our house. The furnace is a separate unit that sits inside the house. When the system is set to cool and the temperature lowered to 78 degrees... the furnace (fan inside the house) comes one. BUT... the outside air conditioning condensing unit won't come on. The fan doesn't spin... and it makes this humming noise. I took a stick to try and move the fan. It moves freely. Is it a bad motor? There's power to the unit. What could be wrong?

Next question is... if we were to replace the condenser unit alone... what's the average cost to replace? What about average cost to "recharge" the existing system with new refrigerant?

Thanks!

It's Hot Here!

Is the compressor running?

I'm in southern Illinois. I'm not sure what labor and freon markup is in your area but we charge 70 dollars an hour for labor and 18 dollars a pound for R22. I'm guessing freon isn't the problem, are you sure the humming your hearing isn't just the contactor inside the unit? I would start by checking the breaker for the air conditioner and make sure there is power to the unit.

How can I tell if the compressor is running? Does it make a noise? Does it spin (eg.. any mechanical parts).

The contactor (per the drawing in the owner's manual) in my unit is located on the bottom of the unit. The humming noise is definitely coming from around the top of the unit, near the motor. Also... when the system is off... the humming stops. When the system is on... the humming starts.

I have a volt meter. I guess I need to check for power but still doesn't explain the noise.


With the freon, the unit isn't blowing out as cold an air as we'd like. Thus, we would like to have it recharged (once we get this unit fixed). About how many pounds of freon you'd think it'll take. Also... how long would it take to have it fully recharged? 1 hr? 2hr?

You need to start by removing the electrical cover on the unit, find the contactor and test the leads that are feeding power to the unit, you should have 240 volts. The compressor when running makes a pumping sound, you would know if it was running It sounds like to me that maybe you don't have power to the unit, start there and get back to me, and I'll try to help.

My advice is that if you do not even know what the compressor is or where it is located, you do not need to be opening the power box and testing for 240 volts. I would say do some phone calling and ask for prices for service calls and minimum charges.

I do agree that the noise you hear is a hum from your contactor being activated.
And that more than likely you have a problem with the high voltage power.

Quote:

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Originally Posted by OneGuyInCA

Help! It's 86 degrees in the house and I have two kids and wife and the darn AC unit won't work.

Here's our situation.

We own an older sears Air Conditioning Condensing Unit (Model 867.816850) that sits outside our house. The furnance is a separate unit that sits inside the house. When the system is set to cool and the temperature lowered to 78 degrees... the furnance (fan inside the house) comes one. BUT... the outside air conditioning condensing unit won't come on. The fan doesn't spin... and it makes this humming noise. I took a stick to try and move the fan. It moves freely. Is it a bad motor? There's power to the unit. What could be wrong?

Next question is..... if we were to replace the condensor unit alone... what's the average cost to replace? What about average cost to "recharge" the existing system with new refrigerant?

Thanks!

It's Hot Here!

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Along the lines of not blowing "cold enough" air... the air handler doesn't blow freezing air, it drops the temp over a period. You don't get an instant blast of freezing cold air. It could be over charged or undercharged with freon. I do agree with letmetellu about calling for a tech to come look at it they will let you know what the freon charge is. There isn't A LOT involved with the condensing unit, but there is A LOT of power involved.

The first place to start is power to the unit though, if there is power to the unit and the compressor runs there could be a problem with the capicator or you may need a new fan motor, hardstart... HVACSERVICE seems to be willing to walk you through the steps though!

Just to give you an idea of prices... in Florida, my company charges $75/hr, and $10/pound of freon R-22, plus price of parts

Quote:

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Originally Posted by sailor612

Along the lines of not blowing "cold enough" air...the air handler doesn't blow freezing air, it drops the temp over a period of time. You don't get an instant blast of freezing cold air. It could be over charged or undercharged with freon. I do agree with letmetellu about calling for a tech to come look at it they will let you know what the freon charge is. There isn't A LOT involved with the condensing unit, but there is A LOT of power involved.

The first place to start is power to the unit though, if there is power to the unit and the compressor runs there could be a problem with the capicator or you may need a new fan motor, hardstart....HVACSERVICE seems to be willing to walk you through the steps though!

Just to give you an idea of prices...in florida, my company charges $75/hr, and $10/pound of freon R-22, plus price of parts

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Thanks for the replies.

So here's the latest of my situation. I ended up calling DialOne. The tech came, did a diagnostic and checked the power. The power was low because of a tripped breaker. The diagnostic check came out fine with the freon level/pressure. He reset the breaker and a $109 later ($69 diagnostic + $40 reset) he fixed it. The contact snaps and then hums (which by the way was the noise I was hearing) Fan comes on. The compressor buzzes... and cool air is once again available He then left.

BUT...

A few days later... here's the situation:

- There's power to the unit.
- The contact snaps then hums.
- But the fan or compressor won't come on.
- Then yesterday... the compressor comes on (buzzing noise) but the fan doesn't run.

Keep in mind this happens intermittently. It'll come on then off again... then on again and off. The furnace inside runs without a problem.

What might be the problem?

Thanks.

It's Hot Here.

You may need go back to the breaker. Do you have 240 volts at the contactor when it shuts off?

Hello again.

So here's an update on my situation.

We eventually found out that the reason for the on/off of the Condenser was because the cooling coil was almost completely blocked with dust partiles, dirt, dog hair, etc. There wasn't any cooling exchange happening. The motor/condensor in the AC has built in thermo protection. It overheated and stopped until it cools off before it runs again. Thus, on/off operation interminttently.

So my wife and I decided that we would just bite the bullet and invest in a new AC/Furance Unit. Our existing one is old (furnance is 1964, AC is 1980's). We got several bids on a replacement. According to the contractors, our setup/configuration is easy. The bids we got ranged from $5,000 to over $9,300 after rebates and all.

In the end, this is what we got:

AMANA 15 SEER 2.5 ton, 2 stage, variable speed DC motor with Electronica Air Cleaner. Lifetime warranty on some parts, and limited on others (not sure which, I need to check).

Is AMANA a good reliable brand??


Thanks!

It's Cool In Here!

I had the same issue with my 5 year old Lennox System (downstairs-outside unit) . After just replacing my upstairs unit (Compressor/Condenser), my downstairs unit fan started to have issues. It would run then stop and making a loud buzzing/humming noise. Luckily I had the old upstairs unit in my garage and pulled out the 3 month old capacitor. I changed the rusted capacitor in the downstairs with the upstairs unit capacitor. Then after switching on the breaker, and turning on the AC the buzzing/humming when away and working normally now.