# Came Home To No Ac Upstairs



## Wolfpackers (May 31, 2007)

Left thermostat on 80* while gone on 6 week camping trip (yesssss). Came home and turned both t'stats down to 70*. Wasn't real hot outside, so inside temps were OK. Next morning, I could tell the upstairs unit wasn't cooling and noticed that the red led "emergency heat" was on. Air didn't feel hot, but was not cool either. Outside unit is not running. Air handler in attic runs and is only 3-4 yr old.

Any HVAC techs out there ? Would love to trouble shoot today and see if I can avoid a repair bill. After 6 weeks on the road, that would just really bite, but have no choice if it's not something I can fix myself.

I have thrown/reset the panel breaker, the air handler breaker and compressor breaker, but to no avail.

Hope there is an easy fix, but am doubting it at this point.

Thanks.

Brent


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## prevish gang (Mar 19, 2006)

How long since you cleaned the condenser coils?

Darlene


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## 3LEES (Feb 18, 2006)

Brent,

Take the thermostat down to 65, set it on cool and auto fan. Check to see if the compressor turns on.

Turn the unit off and wait 15 minutes.

Set the thermostat to 85 and whatever setting you would use for heat from the heat pump. Check to see if the compressor turns on.

If the compressor does not make an attempt to turn on, ( some kind of noise indicating it is trying to start), then you might have a wiring problem. If you had someone tending your yard while you were gone, they might have cut the wire from the compressor to the thermostat. Start there. Also if your thermostat wire is in the attic space, it is possible that rodents could have chewed through the wire.

Then if all else fails, call the HVAC mechanic. I think y'all are gonna need the A/C before long...









Dan


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## Wolfpackers (May 31, 2007)

prevish gang said:


> Brent,
> 
> Take the thermostat down to 65, set it on cool and auto fan. Check to see if the compressor turns on.
> 
> ...


Thanks Dan. will try that in the AM when the DW can work the t'stat while I'm at the outdoor unit to listen.

P.S. My yard is about dead...no rain here for awhile....I'm sure either a neighbor or the yard guy did it at least once during our 6 week absence, but there's no lawn where the outdoor unit is.


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## rjsurfer (Dec 19, 2007)

Dirty and clogged fins can't keep the compressor from coming on, but sometimes if they are really bad the compressor will shut down soon after starting from the over-temp switch tripping. Once tripped, depending on the model AC you have it can take as long as a half hour to reset.

Ron W.


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## Wolfpackers (May 31, 2007)

3LEES said:


> Brent,
> 
> Take the thermostat down to 65, set it on cool and auto fan. Check to see if the compressor turns on.
> 
> ...


The outdoor unit is trying to start, believe it's the compressor I'm hearing. The fan does not turn and there is heat coming up off of the coils. Seems that the fan should come on immediately to pull air thru the coils. I'll check the downstairs unit and see if that's the case on that one. Could be a bad motor on the fan (fingers crossed).

I only tested on cooling, should I have turned it to heat also for any reason ?


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## CamperAndy (Aug 26, 2004)

Sounds like the bearings in your fan have seized.


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## having_fun (Jun 19, 2006)

CamperAndy said:


> Sounds like the bearings in your fan have seized.


If you have to have an A/C problem, thats much better than the compresor. I hate to hear that Brent, the worse thing I had when I got back was a sink that is leaking..........


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## CamperAndy (Aug 26, 2004)

Short term fix is to turn the sprinkler on to the coils to cool them or lay a big box fan on top of the unit to pull air through it.

I would go with the sprinkler.


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## Wolfpackers (May 31, 2007)

Fan bearings are OK, spins easily w/ no noise. Thought it was the starting capacitor, but have ruled that out. I'm thinking it is in the control circuit now, maybe a relay is stuck or not working. Guess it's time to call the man and pay the piper.

Fortunately it only got up to 75* in the upstairs today, using the box fan in the window. Water prices here are too high to spray on the coils unless it doesn't cool down enough to sleep upstairs, but then we can sleep downstairs where the ac does work.

Thanks for all the advice and good wishes.

Brent


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## N7OQ (Jun 10, 2006)

Wolfpackers said:


> Fan bearings are OK, spins easily w/ no noise. Thought it was the starting capacitor, but have ruled that out. I'm thinking it is in the control circuit now, maybe a relay is stuck or not working. Guess it's time to call the man and pay the piper.
> 
> Fortunately it only got up to 75* in the upstairs today, using the box fan in the window. Water prices here are too high to spray on the coils unless it doesn't cool down enough to sleep upstairs, but then we can sleep downstairs where the ac does work.
> 
> ...


I assume you have a split system, if your condenser fan is not coming on then your compressor will kick of on high head. You can use the sprinkler trick in a pinch but don't do it for a expended period of time. The starting cap could be bad or you could have a open motor coil you will need a clamp on amp meter and see if you are pulling any current on the fan motor and is so see if it is excessive per the data plate. These motors go bad all the time I changed 2 of them today. If the starting cap is bad you would be able to start the motor by spinning it by hand as soon as the fan tried to start. Look for the simple things first like a fuse, a bad connection, etc. If there is voltage to the motor and high current then look at the cap or short in the coils, if you have voltage to the motor and no current you have a open coil or connection. If the motor is bad then take it out mark the wires take it to a motor shop buy a direct replacement and install it. You will save a bundle and it is not that hard of a job.


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## Wolfpackers (May 31, 2007)

N7OQ said:


> Fan bearings are OK, spins easily w/ no noise. Thought it was the starting capacitor, but have ruled that out. I'm thinking it is in the control circuit now, maybe a relay is stuck or not working. Guess it's time to call the man and pay the piper.
> 
> Fortunately it only got up to 75* in the upstairs today, using the box fan in the window. Water prices here are too high to spray on the coils unless it doesn't cool down enough to sleep upstairs, but then we can sleep downstairs where the ac does work.
> 
> ...


I assume you have a split system, if your condenser fan is not coming on then your compressor will kick of on high head. You can use the sprinkler trick in a pinch but don't do it for a expended period of time. The starting cap could be bad or you could have a open motor coil you will need a clamp on amp meter and see if you are pulling any current on the fan motor and is so see if it is excessive per the data plate. These motors go bad all the time I changed 2 of them today. If the starting cap is bad you would be able to start the motor by spinning it by hand as soon as the fan tried to start. Look for the simple things first like a fuse, a bad connection, etc. If there is voltage to the motor and high current then look at the cap or short in the coils, if you have voltage to the motor and no current you have a open coil or connection. If the motor is bad then take it out mark the wires take it to a motor shop buy a direct replacement and install it. You will save a bundle and it is not that hard of a job.
[/quote]

Yes, this is a split system. I put the starting cap on the other unit and the fan started up immediately. With the unit on, the fan won't start even with a helping spin. I don't have a clamp on ammeter, but did connect the voltmeter to the black and white wires feeding the fan...got 300 volts, but figure it's the starting cap causing the funky voltage.

I didn't notice any fuses in the control circuits...maybe the spider webs were hiding them?

I was going to call the repair shop in the AM, but with your post, may just take the motor and have it checked at a motor shop. this motor has another set of wires that come out of the motor and then back in and there is a male/female plug in the wire section. Figured this was for repair techs to disconnect the motor....is that correct ?

Thanks for posting.
Brent


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## Katrina (Dec 16, 2004)

Wolfpackers said:


> Fan bearings are OK, spins easily w/ no noise. Thought it was the starting capacitor, but have ruled that out. I'm thinking it is in the control circuit now, maybe a relay is stuck or not working. Guess it's time to call the man and pay the piper.
> 
> Fortunately it only got up to 75* in the upstairs today, using the box fan in the window. Water prices here are too high to spray on the coils unless it doesn't cool down enough to sleep upstairs, but then we can sleep downstairs where the ac does work.
> 
> ...


I assume you have a split system, if your condenser fan is not coming on then your compressor will kick of on high head. You can use the sprinkler trick in a pinch but don't do it for a expended period of time. The starting cap could be bad or you could have a open motor coil you will need a clamp on amp meter and see if you are pulling any current on the fan motor and is so see if it is excessive per the data plate. These motors go bad all the time I changed 2 of them today. If the starting cap is bad you would be able to start the motor by spinning it by hand as soon as the fan tried to start. Look for the simple things first like a fuse, a bad connection, etc. If there is voltage to the motor and high current then look at the cap or short in the coils, if you have voltage to the motor and no current you have a open coil or connection. If the motor is bad then take it out mark the wires take it to a motor shop buy a direct replacement and install it. You will save a bundle and it is not that hard of a job.
[/quote]

Yes, this is a split system. I put the starting cap on the other unit and the fan started up immediately. With the unit on, the fan won't start even with a helping spin. I don't have a clamp on ammeter, but did connect the voltmeter to the black and white wires feeding the fan...got 300 volts, but figure it's the starting cap causing the funky voltage.

I didn't notice any fuses in the control circuits...maybe the spider webs were hiding them?

I was going to call the repair shop in the AM, but with your post, may just take the motor and have it checked at a motor shop. *this motor has another set of wires that come out of the motor and then back in and there is a male/female plug in the wire section. * Figured this was for repair techs to disconnect the motor....is that correct ?

Thanks for posting.
Brent
[/quote]

That plug should be for changing the direction the motor runs. You just unplug it and flip it over and plug it back in.
Normally, I would blame the starting cap, but since you tried it in your other unit, I'd be suspicious of the motor itself.


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## N7OQ (Jun 10, 2006)

Katrina said:


> Fan bearings are OK, spins easily w/ no noise. Thought it was the starting capacitor, but have ruled that out. I'm thinking it is in the control circuit now, maybe a relay is stuck or not working. Guess it's time to call the man and pay the piper.
> 
> Fortunately it only got up to 75* in the upstairs today, using the box fan in the window. Water prices here are too high to spray on the coils unless it doesn't cool down enough to sleep upstairs, but then we can sleep downstairs where the ac does work.
> 
> ...


I assume you have a split system, if your condenser fan is not coming on then your compressor will kick of on high head. You can use the sprinkler trick in a pinch but don't do it for a expended period of time. The starting cap could be bad or you could have a open motor coil you will need a clamp on amp meter and see if you are pulling any current on the fan motor and is so see if it is excessive per the data plate. These motors go bad all the time I changed 2 of them today. If the starting cap is bad you would be able to start the motor by spinning it by hand as soon as the fan tried to start. Look for the simple things first like a fuse, a bad connection, etc. If there is voltage to the motor and high current then look at the cap or short in the coils, if you have voltage to the motor and no current you have a open coil or connection. If the motor is bad then take it out mark the wires take it to a motor shop buy a direct replacement and install it. You will save a bundle and it is not that hard of a job.
[/quote]

Yes, this is a split system. I put the starting cap on the other unit and the fan started up immediately. With the unit on, the fan won't start even with a helping spin. I don't have a clamp on ammeter, but did connect the voltmeter to the black and white wires feeding the fan...got 300 volts, but figure it's the starting cap causing the funky voltage.

I didn't notice any fuses in the control circuits...maybe the spider webs were hiding them?

I was going to call the repair shop in the AM, but with your post, may just take the motor and have it checked at a motor shop. *this motor has another set of wires that come out of the motor and then back in and there is a male/female plug in the wire section. * Figured this was for repair techs to disconnect the motor....is that correct ?

Thanks for posting.
Brent
[/quote]

That plug should be for changing the direction the motor runs. You just unplug it and flip it over and plug it back in.
Normally, I would blame the starting cap, but since you tried it in your other unit, I'd be suspicious of the motor itself.
[/quote]

I agree I too think there is some thing wrong with the motor. When you say you are getting 300 volts is your Multimeter auto ranging? If so make sure you are not reading 300mv instead of 300v I have been fooled more than once this way. But you are on the right track take the motor into a shop and let them tell you if it is bad or not. It is nice that you have 2 units makes it easy to try parts from one to to the other one but be careful, you don't want to end up with 2 dead units. You should have a schematic with your unit if not just google your make and model and you should be able to find one.

BTW I'm off for the next couple of days so if you have any questions ask and I will get back to you sooner.


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## Wolfpackers (May 31, 2007)

Had the motor tested today...bad motor. The motor shop didn't have one in stock but could get it overnight for $75. Called another shop and same thing...only $106. Went to a major wholesaler to HVAC dealers and they sold one to me for $50.

Now if I can just get that danged fan blade assembly off the old motor shaft !!! 18-20 yrs gets a bit rusted up, course I've only owned the home for 7 yrs, so maybe it's not the original fan motor ??

Should be back in business tomorrow...we had a square dance tonite, so that took priority over air conditioning, heh heh.

So thankful it's not hot here and we've been able to make it thru my slow troubleshooting process (it is a wee bit humid tho).

Thanks for all the good Outbacker help and support.

Brent


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## N7OQ (Jun 10, 2006)

Wolfpackers said:


> Had the motor tested today...bad motor. The motor shop didn't have one in stock but could get it overnight for $75. Called another shop and same thing...only $106. Went to a major wholesaler to HVAC dealers and they sold one to me for $50.
> 
> Now if I can just get that danged fan blade assembly off the old motor shaft !!! 18-20 yrs gets a bit rusted up, course I've only owned the home for 7 yrs, so maybe it's not the original fan motor ??
> 
> ...


Glad to here it Brent, and that is a really good price on the motor. For that fan just soak it with some penetrating oil or even spray it with WD-40 and use a drift punch to get it started. I never use WD-40 as a lubricant but it works good for loosening up rust, I also use to when I'm taping aluminum.

My neighbor had their condenser fan replaced by a HVAC company when it froze up and paid almost $500, I told him I would replace it for the price of parts but he didn't want me to do it. This is the same neighbor who turned off the water to his house and when he could not get the water back on he used a pipe wrench on it only problem he was turning it the wrong direction, I had to take him to my house and show him what direction to turn it anyway he broke the stem off and now would have to replace it. I told him I would sweat it off and sweat on a new valve for him but again he so no and called out a plumber and it cost him $300.


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## CamperAndy (Aug 26, 2004)

The ring of rust that tends to form will be worse on top. So once you soak it good with WD-40 or Liquid Wrench. Tap the fan a little bit more down the shaft toward the motor. Then use a file to clean the end of the shaft. The fan will pull off the end of the shaft much easier.

Bill - I have an older neighbor that did not want me to help with things like a dripping faucet until he was charged $600 to replace one (cost of parts $25). Now he asks but thinks he has to pay me to do stuff. Which is also frustrating to deal with.


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## Wolfpackers (May 31, 2007)

N7OQ said:


> The ring of rust that tends to form will be worse on top. So once you soak it good with WD-40 or Liquid Wrench. Tap the fan a little bit more down the shaft toward the motor. Then use a file to clean the end of the shaft. The fan will pull off the end of the shaft much easier.
> 
> Bill - I have an older neighbor that did not want me to help with things like a dripping faucet until he was charged $600 to replace one (cost of parts $25). Now he asks but thinks he has to pay me to do stuff. Which is also frustrating to deal with.


Thanks for the rust info...I already drove the shaft down to almost flush yesterday before I had to go out for the evening. I then sawed the shaft off of the motor so I could get at it better. I did soak it in liquid (whoa, this posted while I was typing) wrench. It'll come off today, one way or the other.









Shame your neighbors don't want to take you up on your hospitality. Non do-it-yourselfers don't realize we diy'ers get a kick out of fixing things, no matter who it's for. We used to use the same model of drip coffee maker and I used to take two of 'em and make a good one out of it..did it a couple of times. I have even found that taking something apart and putting it back together can sometimes "fix" an appliance for unknown reasons..heh, heh.









Getting a late start this AM, better get to it. After the AC is fixed, I gotta change the TV oil after that 6600 mile trip out west & Florida.

Brent


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## Wolfpackers (May 31, 2007)

I just cannot believe this. While putting the new motor on the heat pump cover, one of the studs snapped off as I was tightening the nut....bet I can guess where the motor was made







The studs are smaller than the ones on the old motor, so had to go buy new locknuts. I flipped the stud around so I had enough threads to attach to the heat pump cover. The stud isn't even threaded all the way, just on each end.

After getting the motor installed and all buttoned back up, I set the thermostat to 65* and flipped the breaker by the heat pump and....nothing







. I flipped the breaker several times, but nothing. I took the cover off the control panel and put the voltmeter on the incoming wires...no voltage







. I know there was voltage there a few days ago as I checked to verify that the motor was getting power.

I didn't mention earlier that when I swapped the starting caps on the two units, the downstairs unit would not run after swapping the caps back. I checked the incoming wires for voltage and there too, I had no voltage. After flipping the breaker a half dozen times, it finally came on and has worked fine ever since. Seems to be doing the same thing on the upstairs unit now.

I'm plum out of ideas and now will be looking to see if there is power coming from the main breaker panel to the outside heat pump breaker in the morning. I guess the breaker could have been on the verge of failure and has now failed, but what are the odds ??

Any thoughts on what's happening now ?

Brent


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## N7OQ (Jun 10, 2006)

Wolfpackers said:


> I just cannot believe this. While putting the new motor on the heat pump cover, one of the studs snapped off as I was tightening the nut....bet I can guess where the motor was made
> 
> 
> 
> ...


OK sounds like we might have more than one problem. The first thing you need to do is make sure you have a good voltage source without a good power source you will be spinning your wheels. Go to the breaker panel, measure the voltage at the breaker, it should be a a double breaker tied together you should measure ~115 volts off each breaker to neutral or ground and ~230volts between the 2 wires coming out of each breaker. Check another breaker so you know the meter it working OK. Make sure the connections are good. next check the voltage at the unit a lot of units will have a fuse box at the the unit if so check the fuses and make sure they are good. If you have the fuse block next to the unit make sure you install the fuse block back the same way it can be installed 180 out and it will not supply power to the unit it built this way so you can remove power and leave the fused in the box. If you have power to the unit then look at the Thermostat if it is a programmable stat then change the battery, I have a lot of weird problems caused by weak batteries in the stats.

When I first go to to a dead unit I 1st check the power coming in I then check the control voltage, the thermostat wires coming into a unit will have a red wire or a terminal "R" I measure voltage from red to "R" to ground it should be 24 volts AC in a typical unit but it can be 115 or 220 as well but that is rare. If I have the 24 volts there I will then measure the voltage at the yellow wire or "Y" or"Y1" if you are calling for cooling you should see 24 volts there. If there is no voltage I will put a jumper from "R" to "Y" and see if the unit will come on if it comes on (Might have a time on delay up to 10 minutes) then I check the thermostat and stat wiring. If the unit does not come on then you need a schematic, you will need then go from one device to the next until you find where you loose the voltage. things that can be in series are High limit and low limit switch, freeze up sensor, delay relay etc. A schematic is your best friend in this case. usually there is a schematic on the inside cover of the unit or just stuffed inside the unit or you and do a google search with the brand and model.

BTW if you are missing your 24 volts at the red wire or the ® terminal look for a step down transformer, a lot of them have a fuse inside the transformer.

Let me know if you have any questions.


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## Wolfpackers (May 31, 2007)

Had 230 volts at the main panel breaker and at incoming to non-fused molded case switch on AC disconnect, but 0 volts coming out of MCS. Killed the breaker in the main panel and removed the MCS, checked it for continuity and the side with the hot leg was dead. The plastic piece that holds the main lugs and where the MCS stabs connect had some slight melting and the lug on the hot leg was discolored a bit. The screw that holds the lug to the plastic on the neutral side wouldn't tighten as the plastic boss was partially busted on the back side. Couldn't find parts without buying the whole disconnect, so got one from Lowe's for $15 and just used the back part from the old one as it was attached to the house with something like Hilti nails instead of screws.

All installed and now have AC to sleep in tonite







. Ahhhhhh. (what happened to the shivering smiley face ??)

After fan started, it stopped for a few milliseconds and started back, then did it again. I think we must have had a recloser to operate out on the utility feeder as it was thundering in the distance and it didn't do it again while I was out there watching/listening.

Glad that's over with and I'm sure I saved a good bit of cash by doing it myself. Now I can afford some more diesel fuel with the savings.









N7OQ, sure am glad to know we have an experienced HVAC person on the forum. Really appreciate all the help you and many others have provided.

Thanks,
Brent


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## N7OQ (Jun 10, 2006)

Good deal Brent glad you got it going. So typical you fix one problem just to have another one crop up.



Wolfpackers said:


> Had 230 volts at the main panel breaker and at incoming to non-fused molded case switch on AC disconnect, but 0 volts coming out of MCS. Killed the breaker in the main panel and removed the MCS, checked it for continuity and the side with the hot leg was dead. The plastic piece that holds the main lugs and where the MCS stabs connect had some slight melting and the lug on the hot leg was discolored a bit. The screw that holds the lug to the plastic on the neutral side wouldn't tighten as the plastic boss was partially busted on the back side. Couldn't find parts without buying the whole disconnect, so got one from Lowe's for $15 and just used the back part from the old one as it was attached to the house with something like Hilti nails instead of screws.
> 
> All installed and now have AC to sleep in tonite
> 
> ...


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## skippershe (May 22, 2006)

Wolfpackers said:


> All installed and now have AC to sleep in tonite
> 
> 
> 
> ...


Here it is!









Glad you got your a/c back, that must be a relief


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## Wolfpackers (May 31, 2007)

I checked to disconnect on the other unit and it was warm to the touch (new one isn't) and upon disassembly, found discoloration and slight melting of the plastic part that holds the main lugs, so changed that one too.

Since it isn't very hot here...yet, the bigger relief was not having to pay a huge repair bill after taking our trip out west/SE OB'ers rally for 6 weeks. Can't wait to see the Visa statement to see how much fun we had.









Was the shivering smiley ever part of the ones in the post composing section ? I thought it used to be in there?


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## CamperAndy (Aug 26, 2004)

Wolfpackers said:


> Was the shivering smiley ever part of the ones in the post composing section ? I thought it used to be in there?


Not sure if it was there before the last forum upgrade or not, it is not there now for sure. I am not really into using them but if you start a thread on it I am sure someone will tell you how to down load a million of them. I know there are some cute ones out there. Did I just say cute??


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