: Central A/C - Trane making noise, am I in trouble? moreyes?


rock2me
07-30-2006, 10:08 PM
I have a Trane Central AC unit that is making a strange noise. It sounds like a hissing/bubbling noise when I am outside by the condenser, while the fan is running. Is this normal, or am I need of repair? The unit works fine all day until 3-5pm and then the temp in my house goes from 74 to the low 80's. I normally just let it run and by midnight or early AM it is back to 74. It stays that way until late afternoon. This has been happening for more than a week.

I think it has to do with the Excel energy "System Saver" controller that is attached to my AC unit. Does that cut out the condenser and could that be the reason that it is acting this way? Can I bypass that controller to test my idea?

The unit is a Trane - Elite Super Efficiency, model # BTR736E100A0 , manufacturer: 3/87.

Also, does this unit have a multiple speed fan motor on the condenser unit? I notice that sometimes it runs relatively slow and other times it spins like I would expect it to, fast.

BTW -The temps here in the twin cities have been high (in the 90's) for more than a week now.

Any help - anyone?

Unlogged Texeye
07-30-2006, 10:23 PM
I don't think you should hear a very loud hissing noise. Sometimes you can hear a surging sound when you have a low charge.That would explain why your house temperature rises. It may be freezing the coil up due to an undercharge or just not cooling at full capacity. An undercharged system will give you these symptoms.

Another reason you sometimes hear a hissing sound is when the internal relief in the compressor opens due to high head pressure. A dirty condensor, a fan motor going out, or an over charge will give you this symptom.

When you hear this outside, go inside and listen to the small line feeding your coil. If it is surging or hissing irregulary then it is most likely undercharged.

Have a good one.
Texeye

REW
07-31-2006, 08:22 AM
It would be worth your while to pull the cover and make sure that the unit was absolutely clean.

Often problems are encountered, because the condenser gets plugged with dirt, leaves, or other debris. Sometimes, leaves and other things get in around the motor and fan and cause all sorts of unwanted noise and problems.

Turn off the power to the unit, remove the screws holding the top cover, and use a shop vac or similar device to clean the interior and exterior of the unit. Make sure that the fan is not bent and that it turns easily. If necessary, use a garden hose, to flush the cooling coils from the inside out - so that any debris that might have lodged in the coils will be blown back out from the inside out. Often, if you try to clean the coils by rinsing or blasting the outside of the coils, you will jam the debris further into the coils.

With respect to your question about the energy saver - if necessary, put a voltage monitor on the input to your ac unit. See if the voltage is dropping or going off during these times of "noise on your unit."

You might be in an area of town, that is suffering from a "brownout" situation, due to heavy energy use in your particular area. About that time, the energy use will be at a peak due to the high heat, and heavy use of AC. Put a voltmeter in a house outlet, and see if your voltage is maintaining its expected 120 volts. You might be seeing a voltage sag of 20-30 volts. If this is the case, you might only have 180 volts or so at your air conditioning unit. Low voltage is certainly going to cause issues with the ac unit and its capability to keep your house cool.

Take care
REW

Justfishing2
07-31-2006, 12:37 PM
Some good info. When I have a problem I always start with the basics like cleaning and checking what I can. Like others have said clean the unit. Turn off circuit breaker and take the cover off. Hose if off good from the inside of the coil.to the outside. If it is realy dirty it might be a good portion of your problem.

On the pipes leading to your a/c look to see if there is a sight glass. A few units have these. If you look through it and see a lot of bubbles it is low on freon. If you can't check it that way then it requires use of gauges which probably means calling a tech.

A system low on freon can cause the "A" coil inside the house to freeze up like the old freezers, you know a big block of ice covering the coil. The proplem is you can't see in there. Turn the thermostat up and run just the fan. Then check to see if water continues to drain from the drain tube, if it is frozen you will have a steady trickle. You will need a charge to fix it.

The system is nearly 20 years old so it may be time to replace. New systems have to be a 13SEER or higher. Your old one is likely to be a 7-8.5 Seer. There is a federal tax credit available for certain energy efficient upgrades for 2006 and maybe 2007, covers new window, ac's etc. This might lessen the blow if you need to replace.

rock2me
07-31-2006, 03:01 PM
>It would be worth your while to pull the cover and make sure
>that the unit was absolutely clean.
>
>Often problems are encountered, because the condenser gets
>plugged with dirt, leaves, or other debris. Sometimes, leaves
>and other things get in around the motor and fan and cause all
>sorts of unwanted noise and problems.
>
>Turn off the power to the unit, remove the screws holding the
>top cover, and use a shop vac or similar device to clean the
>interior and exterior of the unit. Make sure that the fan is
>not bent and that it turns easily. If necessary, use a garden
>hose, to flush the cooling coils from the inside out - so that
>any debris that might have lodged in the coils will be blown
>back out from the inside out. Often, if you try to clean the
>coils by rinsing or blasting the outside of the coils, you
>will jam the debris further into the coils.
>
I have cleaned the unit twice this year. Normally, before I turn it on for the year I give it a thorough cleaning. Earlier this week I just blew water through all the fins and it still looks good and clean. The fan spins freely and has nearly zero resistance. If I get it a shove it will spin around a couple times - seems good.

Here it is coming up on 2:00PM and inside the temp is set at 74. It has been 74 all morning and it just started climbing to 76. It is now in the upper 90's outside.


>With respect to your question about the energy saver - if
>necessary, put a voltage monitor on the input to your ac unit.
>See if the voltage is dropping or going off during these times
>of "noise on your unit."
>
>You might be in an area of town, that is suffering from a
>"brownout" situation, due to heavy energy use in your
>particular area. About that time, the energy use will be at a
>peak due to the high heat, and heavy use of AC. Put a
>voltmeter in a house outlet, and see if your voltage is
>maintaining its expected 120 volts. You might be seeing a
>voltage sag of 20-30 volts. If this is the case, you might
>only have 180 volts or so at your air conditioning unit. Low
>voltage is certainly going to cause issues with the ac unit
>and its capability to keep your house cool.

It may be the brownouts as we did lose power last night for several hours. However, it has acted strangely for the better part of a week.

I'm really curious of this unit has a variable speed fan because it sure acts like sometimes it isn't spinning fast enough.

SSH
07-31-2006, 05:12 PM
The System Saver plan probably cycles the A/C on for 10 minutes
and then, off for the next 15 minutes or something similar.

I have something similar with Connexus. I have a separate meter
for the A/C and a radio activiated controller that during peak
times of electrical demand, they cycle mine on for 10 minutes
followed by 15 minutes off. The temperature in my home does creep
up 3-4 degrees in later afternoon/early evening. I receive a
60 % discount for any kilo-watts used by the A/C.

With the temperatures hovering in the upper ninetys, I am sure
the System Saver plan you speak of is whats happening.

You can check outside between your A/C disconnect and the A/C
itself to see if there is a radio controlled box. There are
typically red and green lights indicating the status. I believe
the green means power to A/C, but might be vice-versa.
A quick call to your electrical provider should give you the
correct info.

KHedquist
07-31-2006, 06:02 PM
>I have a Trane Central AC unit that is making a strange
>noise. It sounds like a hissing/bubbling noise when I am
>outside by the condenser, while the fan is running. Is this
>normal, or am I need of repair? The unit works fine all day
>until 3-5pm and then the temp in my house goes from 74 to the
>low 80's. I normally just let it run and by midnight or early
>AM it is back to 74. It stays that way until late afternoon.
>This has been happening for more than a week.
>
>I think it has to do with the Excel energy "System Saver"
>controller that is attached to my AC unit. Does that cut out
>the condenser and could that be the reason that it is acting
>this way? Can I bypass that controller to test my idea?
>
>The unit is a Trane - Elite Super Efficiency, model #
>BTR736E100A0 , manufacturer: 3/87.
>
>Also, does this unit have a multiple speed fan motor on the
>condenser unit? I notice that sometimes it runs relatively
>slow and other times it spins like I would expect it to,
>fast.
>
>BTW -The temps here in the twin cities have been high (in the
>90's) for more than a week now.
>
>Any help - anyone?

Is it the spiny fin or actuall fins?

If it is a spiny coil, you will have to pull the shrouds to clean.

Typically no they dont have 2 speed condensor fans?

Touch the liquid line (the small line coming out of the unit)Be careful is it HOT or warm? Is the suction line (the big line sweating and cool)

It is possible you could either be hearing a low charge or Trane typically use a CLIMATUFF compressor that has a internal bypass to relief over pressure on the condensor, that will hiss.

If it low on gas the comp maybe tripping on a internal safety, and will not restart until the comp cools, it needs suction gas to come back to the comp to keep it cool inside

GOOD LUCK and THANK YOU, moreyes <'{{^}}< :cheers:

http://www.walleyecentral.com/photopost/showgallery.php?cat=500&ppuser=106750

rock2me
07-31-2006, 07:39 PM
moreyes,

It is the spiny coil with a full shroud. Every spring I take the hose and wash it with a spray nozzle, from the outside. I make sure not to have the water on too hard, just enough that I can watch it make it through to the inside cleanly.

Typically no they dont have 2 speed condensor fans? I didn't think so either but sometimes, it is spinning noticeably slower than at other times. If it's not variable, then I must have a bad fan???

Touch the liquid line (the small line coming out of the unit)Be careful is it HOT or warm? No, it is not warm to the touch.

Is the suction line (the big line sweating and cool) Yes, it is cool and sweating.

It is possible you could either be hearing a low charge or Trane typically use a CLIMATUFF compressor that has a internal bypass to relief over pressure on the condensor, that will hiss.

Yes, that is probably it, as it sounds like it has a leak. Similar to what you are describing. That was yesterday but today it has not made that sound.

I just went outside and the unit seems to be working correctly now. The fan is running fast and I am getting cool air in the house - no strange noises. However, my house has slowly crept up from 74 to 83 degrees, starting at about 1:00PM. I think it's about 100 outsie right now.

Can that "Saver" switch be causing me grief - starting it up and shutting it down? I'm ignorant in these areas.

KHedquist
07-31-2006, 07:47 PM
>moreyes,
>
>It is the spiny coil with a full shroud. Every spring I take
>the hose and wash it with a spray nozzle, from the outside. I
>make sure not to have the water on too hard, just enough that
>I can watch it make it through to the inside cleanly.
>
>Typically no they dont have 2 speed condensor fans? I didn't
>think so either but sometimes, it is spinning noticeably
>slower than at other times. If it's not variable, then I must
>have a bad fan???
>
>Touch the liquid line (the small line coming out of the
>unit)Be careful is it HOT or warm? No, it is not warm to the
>touch.
>
>Is the suction line (the big line sweating and cool) Yes, it
>is cool and sweating.
>
>It is possible you could either be hearing a low charge or
>Trane typically use a CLIMATUFF compressor that has a internal
>bypass to relief over pressure on the condensor, that will
>hiss.
>
>Yes, that is probably it, as it sounds like it has a leak.
>Similar to what you are describing. That was yesterday but
>today it has not made that sound.
>
>I just went outside and the unit seems to be working correctly
>now. The fan is running fast and I am getting cool air in the
>house - no strange noises. However, my house has slowly crept
>up from 74 to 83 degrees, starting at about 1:00PM. I think
>it's about 100 outsie right now.
>
>Can that "Saver" switch be causing me grief - starting it up
>and shutting it down? I'm ignorant in these areas.

Yes a system saver switch shuts off the condensing unit, how they wire it in I am not sure? Yes that is what they do, I wa son a restuarant one time they where hot, EXCELL had shut off all there cooling with those switches

Those spiny coils a pain to clean, suppose to be more efficient?

Can you here the compresor running?

Typically the samll line should be warm? But that depends on the outseide temp and internal heat load.

GOOD LUCK and THANK YOU, moreyes <'{{^}}< :cheers:

http://www.walleyecentral.com/photopost/showgallery.php?cat=500&ppuser=106750

rock2me
07-31-2006, 07:57 PM
>Those spiny coils a pain to clean, suppose to be more
>efficient?
Yeah, it's a slow process to run the up over all the coils but they sure look clean now.

>
>Can you here the compresor running?
Yes, it is running now and I'm getting cool air. I see that Saver switch has a green light on it. When it start blowing warm air, I'll go back outside and take a look at that light.


>
>Typically the samll line should be warm? But that depends on
>the outseide temp and internal heat load.
Well, I guess it's about 100 degrees. It is not hot to touch. It feels warm but then again everything feels warm in this heat.

KHedquist
07-31-2006, 07:59 PM
Sent you a email


GOOD LUCK and THANK YOU, moreyes <'{{^}}< :cheers:

http://www.walleyecentral.com/photopost/showgallery.php?cat=500&ppuser=106750

AllenW
07-31-2006, 08:50 PM
Excel usually cycles the condensing unit.
They will cycle the cond unit on and off, and as long as the thermostat is calling for cooling, the inside furnace blower will run.
You can call them for information on the lights on the saver box, might want to look and get the brand name, it'll probably be Scientific Alanta or something like that.

If the inside furnace fan (in the auto posistion) is running and the outside unit is not, chances are they are cycling or the condensing fan motor has stopped or slowed down enough to trip the compressors internal overload.
Might explain the slow fan and hissing.

If the condensing unit fan is stopping or slowing down, I'd have someone check both the motor and capacitor, if it has one, might be a simple fix.
New units are expensive and now is not the time to try and bargain for a new unit.

Your not gonna want to run it this way long, pretty harmful to cycle them off the overload, if that's what's it doing.

Try putting the sprinkler on the condensing coils at a low flow rate, might help enough to get ya though the hot spell.
Light trickle will help a lot.

Al

Unlogged Texeye
07-31-2006, 09:33 PM
I agree with Allen. Keep it simple. If it is 90 plus your condensor fan will not be running on low speed even if it is a two speed. It sounds like a fan motor problem and will cycle the compressor on overload..not good. If it is cycling on overload it will take hours sometimes if it is the heat of the day for the internal circuit to maker again. I too would check the fan motor or capacitor.

Good luck.
Texeye

rock2me
07-31-2006, 10:33 PM
Thanks, everyone, and especially moreyes for the call.

I think I'm going to have to call someone, as it has started hissing again. I went and pulled the shroud and the unit is clean around all the coils. I ran water over everything to get it all cool. Now the compressor is running again and it is blowing cool air.

I popped open the air handler and the coil is definitely not frozen.

The light is still green on the Excel Saver box, throughout this process, so it may not be that. The coil is definitely not frozen.

KHedquist
08-01-2006, 07:04 AM
Glad to be of help

GOOD LUCK and THANK YOU, moreyes <'{{^}}< :cheers:

http://www.walleyecentral.com/photopost/showgallery.php?cat=500&ppuser=106750