There is such a thing as a start and a run capacitor, but I would bet that you'll have one or the other. If you have both, they'll most likely be in a single package with 3 leads.

Good luck,
WallyH

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Originally Posted by WallyHelps

There is such a thing as a start and a run capacitor, but I would bet that you'll have one or the other. If you have both, they'll most likely be in a single package with 3 leads.

Good luck,
WallyH

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Hi Wally - I just got around to replacing the capacitor yesterday morning. Initially I thought that solved the problem because when I came down from the attic, the blower came on.. Of cource it was the morning, and the attic hadn't heated up yet. 1 hour later I tried the blower but it didn't come on. Interestingly enough, when I went back up to the attic; I think it's a relay or transformer (the wires from the T-stat and other wires connected to it and it was 3-4 inches to the right of the capacitor) was really hot, abnormally hot. Above this relay/transformer was a smaller circuit board looking devise with a few wires connected to it also. Any way, I have that relay/transformer out and will replace it. I'll keep you posted.

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Originally Posted by bstanley

Hi Wally - I just got around to replacing the capacitor yesterday morning. Initially I thought that solved the problem because when I came down from the attic, the blower came on.. Of cource it was the morning, and the attic hadn't heated up yet. 1 hour later I tried the blower but it didn't come on. Interestingly enough, when I went back up to the attic; I think its a relay or transformer (the wires from the T-stat and other wires connected to it and it was 3-4 inches to the right of the capacitor) was really hot, abnormally hot. Above this relay/transformer was a smaller circuit board looking devise with a few wires connected to it also. Any way, I have that relay/transformer out and will replace it. I'll keep you posted.

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I'm still really interested in how this turns out! Good luck.

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Originally Posted by WallyHelps

I'm still really interested in how this turns out! Good luck.

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I'll definitely let you know. As I look at what I've recently removed, I'm thinking it's a transformer. It has a fair amount of weight to it. I'd say 5-6 ounces at least. Anyway, I'll go to Grainger on Monday and get this particular part. Also worth noting... the green T-stat wire that is on this transformer or what ever it is, had electric tape for the last 3 inches leading up to the contact. When I replace this part, I'm going to take off that electric tape to see why it's there.

Sounds like you may have a couple of control problems... maybe a fan switch going bad or even a limit switch that is opening in the heat of the attic. Shouldn't happen, but some of these problems are so intermittent that troubleshooting can be a real problem. Unfortunately the best way to locate the problem is when it fail... in the midst of a sweltering attic. If you leave the fan switch in "on" will the fan run constantly or will it still cycle off?

A capicitor for blower shouldn`t cost $5,, is worth trying,, I get them for less than $2,, just make sure you kill the power and ground out the terminals before handleing,

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Originally Posted by wmproop

a capicitor for blower shouldn`t cost $5,,,, is worth trying,,,I get them for less than $2,,,,just make sure you kill the power and ground out the terminals befor handleing,,

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Wow! Where do you get motor start/run capacitors this cheap? I may have a new favorite store!

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Originally Posted by WallyHelps

Wow! Where do you get motor start/run capacitors this cheap? I may have a new favorite store!

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Buy them by the dozen,, Johnstone Supply

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Originally Posted by Missouri Bound

Sounds like you may have a couple of control problems....maybe a fan switch going bad or even a limit switch that is opening in the heat of the attic. Shouldn't happen, but some of these problems are so intermittent that troubleshooting can be a real problem. Unfortunately the best way to locate the problem is when it fail.....in the midst of a sweltering attic. If you leave the fan switch in "on" will the fan run constantly or will it still cycle off?

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Misso - Yes, if I push the fan mode, not auto, the fan/air handler comes on and stays on as long as I do it in the morning.. 7:00 AM or so before the attic heats up. If I wait until 10:00 AM or so, the air handler won't come on. If I leave it in auto and push the cool button, the outside compressor goes on but the air handler in the attic does not. Interestingly, once it's on, it will run for days cycling on and off after reaching the set tempature even with the heat of the attic. The key is turning it on before it's too hot in the attic. I was at several HVAC places today, and most couldn't get this transformer part and some couldn't sell to me because I wasn't a contractor. However several said that either the transformer works or it doesn't. So I guess I can rule out the transformer. This York central air cond is cool only. We have baseboard heat. I'm wondering if the compressor outside has any say on if the air handler comes on or not. That is in an area that get's little sun first thing in the morning but then gets blasted by the sun until 12:00 or so. Well maybe some connections of this transformer were loose and when I put it back in everything will work.

Quote:

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Originally Posted by wmproop

a capicitor for blower shouldn`t cost $5,,,, is worth trying,,,I get them for less than $2,,,,just make sure you kill the power and ground out the terminals befor handleing,,

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WM - I replaced the capacitor but no dice.

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Originally Posted by WallyHelps

Wow! Where do you get motor start/run capacitors this cheap? I may have a new favorite store!

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Wally - I paid $4.60 for the capacitor at Grainger. Fortunatly they had my company as a customer otherwise they wouldn't have been able to sell to me. They're only business to business.

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Originally Posted by WallyHelps

Wow! Where do you get motor start/run capacitors this cheap? I may have a new favorite store!

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Wally - Does the outside compressor have any say as to if the air handler in the attic turns on? i.e. any controls in the outside unit that might be bad causing this problem in the air handler?

Well in case you want to purchase parts yourself, there are PLENTY of supply houses that sell online to consumers. HVAC Parts Outlet is one of them. Can you give the MFG info on the unit itself? I'd like to see a schematic. But I still think it's a matter of replacing parts until you fix the problem, unless you can troubleshoot it while it's failed.
Good luck!

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Originally Posted by bstanley

Wally - Does the outside compressor have any say as to if the air handler in the attic turns on? i.e. any controls in the outside unit that might be bad causing this problem in the air handler?

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I'm not 100% positive, but I think that all the control is done in the thermostat itself. It commands the compressor to turn on, as well as the blower.

Wh

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Originally Posted by bstanley

Wally - I paid $4.60 for the capacitor at Grainger. Fortunatly they had my company as a customer otherwise they wouldn't have been able to sell to me. They're only business to business.

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Yeah, I bought my capacitors at Grainger too, but they were about $12. They were dual units, one for the compressor and one for the fan in a conventional HVAC system. To tell you the truth, I was happy to pay that. I can buy a lot of those for the price of a service call!

Good luck up there,
WallyH

Quote:

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Originally Posted by WallyHelps

Yeah, I bought my capacitors at Grainger too, but they were about $12. They were dual units, one for the compressor and one for the fan in a conventional HVAC system. To tell you the truth, I was happy to pay that. I can buy a lot of those for the price of a service call!

Good luck up there,
WallyH

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I believe I got a corporate discount due to my employer being in their data base.

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Originally Posted by Missouri Bound

Well in case you want to purchase parts yourself, there are PLENTY of supply houses that sell online to consumers. HVAC Parts Outlet is one of them. Can you give the MFG info on the unit itself? I'd like to see a schematic. But I still think it's a matter of replacing parts until you fix the problem, unless you can troubleshoot it while it's failed.
Good luck!

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I will. I'll be back up there Friday... loosing a few pounds in the blistering heat of the attic, to put the old transformer back in. I noticed on the air handler that there was a sticker with information on it. I'll right it down and let you know. I know that it's a York around 9 years old but I'll get more detailed info.

Quote:

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Originally Posted by Missouri Bound

Sounds like you may have a couple of control problems....maybe a fan switch going bad or even a limit switch that is opening in the heat of the attic. Shouldn't happen, but some of these problems are so intermittent that troubleshooting can be a real problem. Unfortunately the best way to locate the problem is when it fail.....in the midst of a sweltering attic. If you leave the fan switch in "on" will the fan run constantly or will it still cycle off?

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Misso - the fan switch... is that literally a on-off switch? Up at the blower, the main power goes to a light switch... it looks like a regular 2-pole type on-off light switch. From there it goes to the transformer. Is it possible that this switch would be affected by the heat of the attic?

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Originally Posted by bstanley

Misso - the fan switch... is that literally a on-off switch? Up at the blower, the main power goes to a light switch... it looks like a regular 2-pole type on-off light switch. From there it goes to the transformer. Is it possible that this switch would be affected by the heat of the attic?

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I'll jump in here...
My guess is that this switch is just for safety. You can kill power to the blower so it would be safe to stick your hands in there. I would seriously doubt this would contribute to the problem, but while you're replacing things it would be a cheap experiment. Just kill power at the breaker beforehand!

WallyH

NO. The fan switch on the thermostat is just a control. There will be a contactor of some sort that the fan switch controls in the air handler. On my heat pump, for example the fan would continue to run after the air conditioner was satisfied. It turned out to be a fan switch (relay) which was sticking. After replacing it the switch worked normally. And some furnaces have a fan control which sensed heat rise after a burner fires up and starts the fan and allows it to run after the furnace flame kicks off to circulate and to cool the heat exchanger.