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nickc50310
join:2009-04-06
Des Moines, IA

nickc50310

Member

AC troubles! Need help!

Hi guys! Since I always get awesome home advice on here, I figured this was best place to post this!

Well, as Im sure you can guess, its hotter than hell here in Iowa and Im having central AC issues. A few months ago i had it checked out and the tech said there was nothing he could do. The unit was built in 1962 and is matched up with my newer furnace so its not working effiecently. Then, last month, the fan started acting up. If the unit turns off, the fan on the outside ac unit wont kick back up without a little jump start from me. Because of this, I just set the thermostat super low so it never stops. Well, I got my power bill and it wasnt pretty as you can imagine. LOL! its far worse than I thought it would be. The central ac unit has corroded fins and is dying to say the least. On a recent 98 degree day, it got up to 80 inside my house.

My house is about 800sf with a nice finished basement that I spent a lot of time in. I cant really spend 2k+ on a new central unit right now so i am planning on buying a couple of window units. I plan on running the fan only on my central system to hopefully circulate the cool air around the house including the basement since i wont have a window unit down there.

I plan on getting this unit for the bedroom:
»www.homedepot.com/Featur ··· Id=10053

And this unit for living room/dining room/kitchen which together couldnt be over 400sf.
»www.homedepot.com/Featur ··· Id=10053

Am I taking the best approach for my situation? Will the air be spread out enough by my central blower that my basement will be cool also? Will these window units be cheaper to run thant my current central unit?

I do have a dehumidifier in the basement btw.

Any pointers ideas or tips will be greatly appreciated! Thanks guys!

mityfowl
Premium Member
join:2000-11-06
Dallas, TX

mityfowl

Premium Member

48 year old AC?

Must be some kind of record.

Anything you do will be an upgrade in efficiency.
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

TheMG to nickc50310

Premium Member

to nickc50310
"nothing he could do"

Bullshit!

You just need a new capacitor for the fan motor. It's like $30 MAX and not all that hard to install yourself (just be sure to turn off the breaker first).

You can get the capacitor rating that you need by looking at the existing capacitor, or the motor it will be written there too (if it's still readable.
nickc50310
join:2009-04-06
Des Moines, IA

nickc50310

Member

The fan was working fine when it was checked back in June. The issue of the fan needing a jump start has only started occurring recently. Where is the capacitor in the fan motor? Also, the fan motor was replaced 3 years ago.
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

1 edit

TheMG

Premium Member

said by nickc50310:

The fan was working fine when it was checked back in June. The issue of the fan needing a jump start has only started occurring recently. Where is the capacitor in the fan motor? Also, the fan motor was replaced 3 years ago.
The capacitor is normally located in the electrical compartment (where the wires go in) of the A/C condenser unit.

Capacitors fail over time but can also fail rapidly in some cases. It could have been going bad the whole time, but still just enough to get the motor spinning.
nickc50310
join:2009-04-06
Des Moines, IA

nickc50310

Member

Got it. Any tips as to what it would look like? Obviously I know what a capacitor looks like but I would assume there will be more than one in there.

Furthermore, if this capacitor has been failing for a while, could it cause the fan to not run at full speed and get as cold as it used to?
nickc50310

nickc50310

Member

Ok, I just googled it and can see what Im looking for. Im also going to run some cleaning foam through the fins and also straiten some of the bent fins.
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

TheMG to nickc50310

Premium Member

to nickc50310
said by nickc50310:

Got it. Any tips as to what it would look like? Obviously I know what a capacitor looks like but I would assume there will be more than one in there.

Furthermore, if this capacitor has been failing for a while, could it cause the fan to not run at full speed and get as cold as it used to?
Depending on the unit, there may be one or two individual capacitors, or one "dual" capacitor (3 wires). If there is two capacitors it's easy, the smaller one is for the fan motor. If it's a dual capacitor it has to either be replaced with an equivalent dual capacitor, or it can be replaced by two individual capacitors of proper rating. I don't think your unit has one of those dual capacitors though, as you didn't mention anything about the compressor having problems starting.

Yes, a bad capacitor can affect the speed of the fan in some cases. Really depends on the motor.

Bent/dirty fins and anything else to reduce the airflow through the coils will affect the efficiency of the unit.
nickc50310
join:2009-04-06
Des Moines, IA

nickc50310

Member

Got it! And to discharge the capacitor I just bridge it right? Where should I go to buy a new capacitor?
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

2 edits

TheMG

Premium Member

Local HVAC supplier, internet, etc.....

"The central ac unit has corroded fins and is dying to say the least. On a recent 98 degree day, it got up to 80 inside my house."

And that's with the A/C running non-stop? Is the house insulated?

If the answer is "yes" and "yes", I'd stop what you're doing right now and consider replacing the system!!!

jrs8084
Premium Member
join:2002-03-02
Statesville, NC

jrs8084 to nickc50310

Premium Member

to nickc50310
If your coil is old and corroded as you state, I would stay clear of the cleaning foams right now. (They tend to be very aggressive.) Use straight water and a hose with gentle water pressure. Take your time.
scross
join:2002-09-13
USA

scross to nickc50310

Member

to nickc50310
As others have said, this could be a simple capacitor problem, easily rectified for minimal expense. But it could also be a fan motor problem (bearings could be dying, or whatever), which would be considerably more expensive. You said the motor is only 3 years old, so this is unlikely - although I had one die at 5 years because I neglected to oil it, as you're supposed to do on this particular motor every year or so. Many newer motors are sealed and require no oiling, at least theoretically.

As an FYI, when they replaced the motor they should have also replaced the capacitor as a matter of routine. Right now in my unit there is an old dual capacitor (the motor side is disconnected, but compressor side is still in use), plus a separate motor cap they added when they replaced the motor. This saved them from having to find a perfect match for the dual capacitor, since they probably didn't have one on the truck.

Some pictures and make and model number info (if you can find it) might be helpful here.
scross

1 edit

scross to mityfowl

Member

to mityfowl
"48 year old AC?
Must be some kind of record.
Anything you do will be an upgrade in efficiency."

Mine is at 25+ years and still going strong - knock on wood!

When my HVAC guy was here a couple of years ago I talked to him about replacing the unit with a more efficient one. He hemmed and hawed when I asked him how quickly he thought it might pay for itself with energy savings; I came to the conclusion that the answer was probably "not in your lifetime". He also hemmed and hawed when I asked him how old his own unit was at home; I got the impression that the correct answer was probably "older than yours".

jrs8084
Premium Member
join:2002-03-02
Statesville, NC

jrs8084

Premium Member

My unit is 18 y/o, and by SEER rating is low by today's standards. From April to Oct-I "set it and forget it" (other than minimal setbacks during day/night), and the increase in my electric bill during these months is minuscule (I have never seen more than a $35 increase/month).

The place I work at was built in stages, starting in '54. As such, there are LOTS of small units here and there to cool offices, break rooms, etc. There are a few units that date to the 60s, and, while they look pretty sad, they give the least amount of trouble-especially compared to the brand new crap.

BryanInPHX
Premium Member
join:2001-03-06
Phoenix, AZ

1 edit

BryanInPHX to nickc50310

Premium Member

to nickc50310
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nickc50310
join:2009-04-06
Des Moines, IA

nickc50310

Member

Hi guys! Thanks for all the awesome help. I just opened up the unit and it was filthy. The coils were almost completely clogged. This after the asshat who looked at it in May said he cleaned it all out.

I cleaned it out and it seems to be working better. Next, I am going to straighten some of the bent fins and run some foam cleaner through the coils. The capacitor has been replaced at some point because I could see the old unhooked one sitting in one spot and another one in a different spot, wired up to the fan. Its wired in a way that I dont want to mess with it so I am going to call the repair placed and see how much to replace my coil. If its alot, Ill just do it myself.
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

1 edit

TheMG

Premium Member

said by nickc50310:

Hi guys! Thanks for all the awesome help. I just opened up the unit and it was filthy. The coils were almost completely clogged. This after the asshat who looked at it in May said he cleaned it all out.
No wonder you couldn't get the house below 80 on a 98 degree day!

What do you mean by "wired in a way that I dont want to mess with"?

There should be only two terminals on the capacitor. There may be more than one wire to the same terminal. Just make sure to keep them together (easy way: wrap some tape around the wires going to the same terminal before disconnecting them). The capacitor itself does not have a polarity, it can be flipped around and will work just the same.

jrs8084
Premium Member
join:2002-03-02
Statesville, NC

jrs8084 to nickc50310

Premium Member

to nickc50310
said by nickc50310:

Its wired in a way that I dont want to mess with it so I am going to call the repair placed and see how much to replace my coil. If its alot, Ill just do it myself.
You have the tools/knowledge to replace your coil yourself and you come to a message board for advice for poor cooling?

Changing a coil out is not like changing a light bulb. Maybe you meant changing the cap out.
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

TheMG

Premium Member

said by jrs8084:

You have the tools/knowledge to replace your coil yourself and you come to a message board for advice for poor cooling?

Changing a coil out is not like changing a light bulb. Maybe you meant changing the cap out.
I'm going to take a guess and say that he intended to say "cap" not "coil".
nickc50310
join:2009-04-06
Des Moines, IA

nickc50310

Member

Yeah I meant to say coil. At any rate, Im back to my original plan. Im going to get two window units today. So that brings up my original question- will running my blower help to spread the cool air from the window units around my house, including the basement?

Ive decided to do this because the coil is just completely hosed. I would say about 25% of the coils are completed corroded and about another 15% are bent completely over. Its 75 outside and 72 in my house with the air running. At this rate, no matter what I do, the air is going to run non stop.

Thoughts?

whizkid3
MVM
join:2002-02-21
Queens, NY

whizkid3 to nickc50310

MVM

to nickc50310
48 years old?

Be happy. You have set a new record for longevity. Its exceeded typical end-of-life by about 30 years. No wonder it was sucking down electricity.

Get a new air-conditioner. In electricity costs alone, it will probably pay for the new unit and installation in a few years.
nickc50310
join:2009-04-06
Des Moines, IA

nickc50310

Member

Yeah Im going to get new central air next year. Ill survive the rest of the summer with window units. I have a GF who wants to get married so im trying to save some coinage. LOL!

Karride
Slower Traffic Keep Right
Premium Member
join:2000-04-17
Germantown, TN

Karride

Premium Member

said by nickc50310:

Yeah Im going to get new central air next year. Ill survive the rest of the summer with window units. I have a GF who wants to get married so im trying to save some coinage. LOL!
Heh, buy it now, once your married, you won't have the money for a new A/C.
TheMG
Premium Member
join:2007-09-04
Canada
MikroTik RB450G
Cisco DPC3008
Cisco SPA112

1 edit

TheMG to nickc50310

Premium Member

to nickc50310
said by nickc50310:

I have a GF who wants to get married so im trying to save some coinage. LOL!
That's what parents are for. You shouldn't have to pay a dime for your wedding.
nickc50310
join:2009-04-06
Des Moines, IA

nickc50310

Member

Hahah! Yeah that wont work really. I will say that I am pleased with the AC so far. The two window units keep things plenty cool in the house and Im sure will save me some money. The only disadvantage is that the basement doesnt stay very cool since no cool air is going down there but even that isnt bad as long as I have a fan blowing down there.

MineCoast
Premium Member
join:2004-10-06
Pensacola, FL

MineCoast to TheMG

Premium Member

to TheMG
said by TheMG:

"nothing he could do"

Bullshit!

You just need a new capacitor for the fan motor. It's like $30 MAX and not all that hard to install yourself (just be sure to turn off the breaker first).

You can get the capacitor rating that you need by looking at the existing capacitor, or the motor it will be written there too (if it's still readable.
^Exactly what he said.

I had the EXACT same thing happen to my unit last summer. Thankfully my uncle is an electrician as well as knew some HVAC tech's and was able to make the repair. My situation was a little odd... the fan would come on for a few minutes then quit, or the fan would go backwards, or wouldn't come on at all until you hit the fan to get it moving. Since we had the unit opened up, we also went ahead and replaced the fan motor. It cost us $50 for the cap and motor, not too bad.