Air conditioner- Help

[phebus]

The air conditioner here at my Havasu house isn't working. It is a Trane roof mounted 3.5 ton unit. It turns on, and seems to run O.K. The compressor unit runs, but the air coming through the vents seems weak and the house isn't cooling down.(new filter already installed)
Any air conditioning techs out there that can give me some troubleshooting tips? It's Sunday so I don't doubt I will be able to get it fixed today.
Also, any leads on a good repair person in Havasu would be appreciated.
Thanks

[phebus]

It doesn't seem to be moving much air!! Back to the roof, and try to find where the squirrel cage is to see if it is running.
Someone please help me, I have an angry wife!!! :mad:

[LASERRAY]

When you say that the air is "weak", I assume that you mean that you have low air volume? If so then make sure the blower is running, and running at full speed. Take an amp draw off the motor and compare to the R.L.A. or F.L.A. rating on the motor tag or unit tag.
You say the filter is clean, what about the evaporator coil? Sometimes with lack of maintenance they tend to get matted with debris, although that's an extreme case.
Are your ducts crushed?
Is the squirel-cage blower tight on the motor shaft?
Another way to tell if it's a true airflow problem is to look and see if the unit is "iceing-up".
If all of the above look fine, let me know and will try some more diagnosing. ;)

[Tom Brown]

If it's not moving air, there is obviously a blockage. Perhaps the a-coil is iced up or the return air grates are blocked with furniture or something.
If the return air is blocked, the evaporater will ice up so you will have two problems. Clear the vents, let the coil thaw, and then try it again.
Low coolant will also cause the coil to ice over.

[phebus]

When you say that the air is "weak", I assume that you mean that you have low air volume? If so then make sure the blower is running, and running at full speed. Take an amp draw off the motor and compare to the R.L.A. or F.L.A. rating on the motor tag or unit tag.
You say the filter is clean, what about the evaporator coil? Sometimes with lack of maintenance they tend to get matted with debris, although that's an extreme case.
Are your ducts crushed?
Is the squirel-cage blower tight on the motor shaft?
Another way to tell if it's a true airflow problem is to look and see if the unit is "iceing-up".
If all of the above look fine, let me know and will try some more diagnosing. ;)
The air return duct is clear, and all ducting is fine. The coils are also clean. I don't have my amp meter out here in Havasu with me, so to I can't meter anything.
The air volume seems really low, you can barely feel any air coming out of the vents. The unit had ice on the lines from the compressor, so I let it sit and de-ice, but when I turned it back on it didn't make a difference. I am trying to figure out what panel to remove to get to the blower unit to check it.

[LASERRAY]

The air return duct is clear, and all ducting is fine. The coils are also clean. I don't have my amp meter out here in Havasu with me, so to I can't meter anything.
The air volume seems really low, you can barely feel any air coming out of the vents. The unit had ice on the lines from the compressor, so I let it sit and de-ice, but when I turned it back on it didn't make a difference. I am trying to figure out what panel to remove to get to the blower unit to check it.I'm assuming that your blower is direct-drive and not belt-drive. Very rarely will you see a belt-drive blower outside of a commercial application.
The ice build-up is a direct result of the airflow problem, so It doesn't sound like the unit is low on refrigerant if in fact you did allow all the ice to melt before you re-tried it and found that you still had low airflow.
Just double check to make sure that all your supply registers ( grilles ) are open and your return-air grille is not blocked with furniture. :smile:

[phebus]

There is no blockage, and the unit was working fine yesterday, and now it isn't and there have been no changes.
In the process of removing covers to find the blower, the coils in the unit that aren't on the compressor are frozen solid. The unit is turned off again with the cover off to let it melt.
I still haven't found the blower unit, and I have almost every cover off of the thing. Would it be part of the roof mounted unit, or would it be down in the attic? I think it is self contained on the roof, but I can't find the darn thing.

[LASERRAY]

I'm assuming that your blower is direct-drive and not belt-drive. Very rarely will you see a belt-drive blower outside of a commercial application.
The ice build-up is a direct result of the airflow problem, so It doesn't sound like the unit is low on refrigerant if in fact you did allow all the ice to melt before you re-tried it and found that you still had low airflow.
Just double check to make sure that all your supply registers ( grilles ) are open and your return-air grille is not blocked with furniture. :smile:As far as the blower motor itself which sounds like the problem, if you observe the motor not turning, but perhaps humming and attempting to start, or turning but at less then about half speed, then it could be a bad "run capacitor" which is an externally mounted motor capacitor which aids the motor in starting. If this has failed, the motor wont run. The capacitor has a uf (micro-fared) rating ( anywhere from 5 uf to 15 uf for most residential applications of fractional horsepower motors) and a voltage rating ( 370 or 440 vac ). These are inexpensive componants to replace, but it's not like they stock them down at wallmart. :D

[gramps]

you might want to look here http://trane.com/Residential/TraneOwners/OwnersManuals.aspx

[phebus]

I haven't fond the blower unit, but there is a humming sound coming from the unit. I have exposed the electrical panel with the capacitors though. Do they sell them at places like Home Depot?

[LASERRAY]

I still haven't found the blower unit, and I have almost every cover off of the thing. Would it be part of the roof mounted unit, or would it be down in the attic? I think it is self contained on the roof, but I can't find the darn thing.
There's your problem!!!
Someone stold your Blower !!!!!!!
Good work! :rollside:
Just make suree that ALL THE ICE IS MELTED before you retry it again. If the airflow is ok at that time, then your unit is low on refrigerant. If the airflow is still non-existant, see my post before this one on motors and capacitors.

[Kachina26]

If my air goes down I'm calling you Ray!

[LASERRAY]

If my air goes down I'm calling you Ray!I'd be more then happy to help you out Randy. :cool:

[BoatPI]

Ypou may be suprised that many AC guys will come out on a weekend. This is Havasu. Now, will they have a new blower motor with them? Perhaps, if not in the shop. I just used Mercury Air Co.. Excellent new 5 ton unit (Trane), and undercut others by $500. Try setting the thermostat to fan ON, but with the cooling off. Then will confirm the broken blower. If it is NOT a direct drive, you may be in luck as it could be a fan belt. Make sure the breaker is OFF!. AT 220 volts, it is unforgiving, and yes, the blower could be a 220 volt unit too.

[phebus]

O.K. I found the blower motor, it was behind the one cover I couldn't get off. I couldn't get it off due to the ice build up I found behind it (1/2-1" thick).
The blower is not working. I figure it is probably the capacitor, but I don't know which one. I see three in the electrical panel. One big round one, one medium oval, and one small oval. Any idea which one it is? I can take pics and post them if that would help.

[LASERRAY]

O.K. I found the blower motor, it was behind the one cover I couldn't get off. I couldn't get it off due to the ice build up I found behind it (1/2-1" thick).
The blower is not working. I figure it is probably the capacitor, but I don't know which one. I see three in the electrical panel. One big round one, one medium oval, and one small oval. Any idea which one it is? I can take pics and post them if that would help.First things first. As Boat PI stated, TURN THE POWER OFF!!!!! Then trace the Brown and Brown/White capacitor leads from the motor back to the capacitor. Or look at the wiring diagram/schematic. :shift:

[Hal]

Oops I was to late.

[Tom Brown]

I'll be surprised if it's the capacitor. It's usually the motor.
By the way, once those things ice up, it takes a long time for them to clear. It's not like they will thaw in 10 minutes.

[phebus]

The power is off to the unit, and I am being carefull not to get zapped by the capacitors. I have the schematic, and the capacitors are wired as follows:
Small oval- purple/brown
medium oval- yellow/ brown
Coming off the blower unit are- Yellow, Red, Brown, Black, Purple.
The capacitors are identified on the schematic, and the small one is called the outdoor fan capacitor, and the larger one the indoor motor capacitor. Yes, common sense says it should be the outdoor fan one, but since I don't have an indoor motor I have to make sure it doesn't refer to the blower.

[gramps]

watchin' this is better than anything on TV right now...........

[phebus]

I'll be surprised if it's the capacitor. It's usually the motor.
By the way, once those things ice up, it takes a long time for them to clear. It's not like they will thaw in 10 minutes.
Seeing how much ice there is, it will take awhile even it Havasu heat. The blower motor is not running though.
I am putting some beer on the frozen coils, so when I am up on the roof I will have cold ones waiting and not have to go up and down the ladder to get more.

[LASERRAY]

The blower is not working. I figure it is probably the capacitor, but I don't know which one. I see three in the electrical panel. One big round one, one medium oval, and one small oval. Any idea which one it is? I can take pics and post them if that would help. AS I stated earlier, if the motor is humming, or running slow it's probably the run cap. Is the motor warm?
If the motor is cold, not humming, and not turning it's an "open" motor meaning the windings are burned-out, or the internal overload is permanently "open".
It may also be a bad motor relay. Maybe you're not getting power to the motor. A meter would come in handy right about now. :)

[Hal]

Its most likely a heat pump. If so just turn it on heat untill the ice melts off the evap coil. You wont need the evap blower motor running to do this. and you can leave the blower panel off and watch the ice melt.

[LASERRAY]

The capacitors are identified on the schematic, and the small one is called the outdoor fan capacitor, and the larger one the indoor motor capacitor. Yes, common sense says it should be the outdoor fan one, but since I don't have an indoor motor I have to make sure it doesn't refer to the blower.The "outdoor" fan motor is the Condenser fan motor. The "Indoor" fan motor is the blower. Indoor/outdoor refers to inside or outside of the unit cabinet. You're concerned with the "Indoor" fan motor.

[Tom Brown]

It sounds like you and Ray are all over it but I'll just add this...
I would give the fan a push and see if it spins freely. If so, it could be a bad starting coil and it might run if it comes to rest at a different spot. If it runs, turn the fan to 'on' at the thermostat and let it run continuous until a technician can come to replace the motor.
By the way, I would think outdoor means condenser and indoor means evaporator.

[LASERRAY]

Its most likely a heat pump. If so just turn it on heat untill the ice melts off the evap coil. You wont need the evap blower motor running to do this. and you can leave the blower panel off and watch the ice melt.I would have to advise against this. With the indoor blower motor not running you'll be sending hot gas back to your compressor which will cause the head pressure to exceed 400 psig, possibly damaging the internal pressure relief valve, or suction valves. :cool:

[phebus]

O.K. I've been up and down the ladder so many times it feels like I have run a 10K. Besides that, I have the wife bitching at me for being such a cheap ass for not just calling someone to repair it.
Here is where I stand. The fan motor is now running. I don't know if there was a bad contact, or as someone suggested, maybe a flat spot on the motor. I have it turned it to heat to help defrost, and I am going up on the roof with my beer to watch it.

[LASERRAY]

O.K. I've been up and down the ladder so many times it feels like I have run a 10K. Besides that, I have the wife bitching at me for being such a cheap ass for not just calling someone to repair it.
Here is where I stand. The fan motor is now running. I don't know if there was a bad contact, or as someone suggested, maybe a flat spot on the motor. I have it turned it to heat to help defrost, and I am going up on the roof with my beer to watch it.To bad you live so far away. I'd come over and help you............................................... ........................... Drink your beer, :)

[Hal]

How you going to get hot gas back to the compressor? its no different than when the unit goes into defrost while in the heat mode. I should have added to shut it off when the ice is gone. But I think he would know that.

[phebus]

At least I found out my house is very well insulated. It stayed HOT all night!!! :mad:

[Tom Brown]

It stayed HOT all night!!! :mad:
It might have cooled off if you had sent your wife over to her sisters to sleep. :D

[phebus]

If the unit starts working again, should I chalk the problem up to the super high humidity we have been having (monsoons), or do you think I have a problem with it. I don't know if the problem was the blower fan not running, or if that problem came on after the icing up.

[Tom Brown]

Why not save a few bucks by not replacing the motor. :)
Have a divorce attourney standing by, though. :D

[gramps]

it's too soon to make a decision...............you need a few more beers.

[BoatPI]

And the monsoon issue with icing is not all that uncommon in Havasu. This can be avoiding if you leave the fan in the on position during high humidity times. this keeps air moving over the coil 24/7. There could be other issues too, like low freon. Or some of the registers in the house are closed, thus reducing air flow. Newer 14 and above SEER units tend not to ice up as quickly.

[LASERRAY]

If the unit starts working again, should I chalk the problem up to the super high humidity we have been having (monsoons), or do you think I have a problem with it. I don't know if the problem was the blower fan not running, or if that problem came on after the icing up.More then likely the motor failed and cause the iceing, not the other way around. I've heard of extreme humidity causeing iceing problems but have never really seen it in my day to day travels.
Question: What temp do you keep your stat set? A setting below 70 degrees will more then likely cause iceing. Keep it set above 70 degrees.

[Hal]

If the unit starts working again, should I chalk the problem up to the super high humidity we have been having (monsoons), or do you think I have a problem with it. I don't know if the problem was the blower fan not running, or if that problem came on after the icing up.
Icing up first could very well have been the problem and then the blower motor just over heated and shut off from lack of cooling air over it. Just keep your stat set at an obtainable temp where the unit will not run constantly. But like Ray said its usually a bad motor that causes the icing.
My timing has been way off in these posts. trying to watch Anaconda on tv and when I come back and don't hit refresh I am way behind. :D

[Tom Brown]

More then likely the motor failed and cause the iceing, not the other way around.
I'm with you, Ray. There is a chance it could have been the icing causing the motor to cut out on thermal protection, though.
Maybe you should walk him through checking his refrigerant loads with the superheat method? :D

[LASERRAY]

I'm with you, Ray. There is a chance it could have been the icing causing the motor to cut out on thermal protection, though.
Maybe you should walk him through checking his refrigerant loads with the superheat method? :DThen he's got to dig-up his sling sycrometer, superheat thermometers, and superheat slide chart. It's just not worth-it!!! :D

[LASERRAY]

How you going to get hot gas back to the compressor? its no different than when the unit goes into defrost while in the heat mode. I should have added to shut it off when the ice is gone. But I think he would know that.It has the same effect as the condenser fan motor not running in cooling, what happens to system pressure? It goes through the roof!!! And hopefully there's a High Pressure cut-out switch set at 410 psig to shut-down the compressor.
When a heat pump goes into defrost, the reversing valve switches-over to cooling, and the hot gas/ liquid from the indoor coil gets dumped into the suction accumulator which is just upstream from the compressor, as I'm sure you know. :)

[Hal]

If you had ice all over your condenser coil you would'nt have hi pressure problem untill the ice melted. Its just like running water over the condenser coilyou don't need a cond. fan running then.

[LASERRAY]

If you had ice all over your condenser coil you would'nt have hi pressure problem untill the ice melted. Its just like running water over the condenser coilyou don't need a cond. fan running then.That's right. But, His ice build-up was on the indoor coil, not the outdoor coil. ;)

[mike37]

If it's not moving air, there is obviously a blockage. Perhaps the a-coil is iced up or the return air grates are blocked with furniture or something.
If the return air is blocked, the evaporater will ice up so you will have two problems. Clear the vents, let the coil thaw, and then try it again.
Low coolant will also cause the coil to ice over.
right on the money

[Hal]

That's right. But, His ice build-up was on the indoor coil, not the outdoor coil. ;)
Whats the differance if your running in the heat cycle with the evap fan off and a iced up evap coil? Its the same as running it in cooling with ice on the condenser.

[LASERRAY]

Whats the differance if your running in the heat cycle with the evap fan off and a iced up evap coil? Its the same as running it in cooling with ice on the condenser.This is true.

[gramps]

the big question is how many beers has he been able to cool off and dispose of so far!!!!!

[phebus]

All seems well now, temp is coming down. We generally keep the thermostat set at 74*, and the fan set on auto. I will keep the fan set to on from now on as suggested. I'm hoping the problem was an icing issue caused by the high humidity, and not a bad motor.
Off to the lake now, and hopefully coming home to a cool house.
Thanks to all for their help.
Rick

[Hal]

The big question is whos going to win at the Glen today? I like both the Gordons.

[LASERRAY]

All seems well now, temp is coming down. We generally keep the thermostat set at 74*, and the fan set on auto. I will keep the fan set to on from now on as suggested. I'm hoping the problem was an icing issue caused by the high humidity, and not a bad motor.
Off to the lake now, and hopefully coming home to a cool house.
Thanks to all for their help.
RickI'll keep my fingers crossed. Have a good day on the water. :chi:

[ROZ]

This is true.
Yea, probably. He and trailer Park Cassanova have posted really good hvac advise... Info has totally helped meout... I think they each have been doing this kinda work for 25 years plus :rollside:

[LASERRAY]

Yea, probably. He and trailer Park Cassanova have posted really good hvac advise... Info has totally helped meout... I think they each have been doing this kinda work for 25 years plus :rollside: Yes, he seems very knowlegeable. I wasn't aware that there were more then a couple HVAC techs on the board. Tom Brown is a former tech as well, as it turns-out, and I know about TPC/Flying Tiger. ;) And I've been one for the last 18 years.

[ROZ]

What hasn't Tom done? :idea: :mix:

[LASERRAY]

What hasn't Tom done? :idea: :mix:Oh, uh, I don't know!
What about being tied to a giant Sequoia, and beaten with warm squash by jack Mormons, disquised as Amish? :D

[Dr. Eagle]

Yes, he seems very knowlegeable. I wasn't aware that there were more then a couple HVAC techs on the board. Tom Brown is a former tech as well, as it turns-out, and I know about TPC/Flying Tiger. ;) And I've been one for the last 18 years.
I know a thing or two about HVAC too. There is an on and an off switch for starters... always check the position of this switch before commencing troubleshooting...

[havasu p/t er]

OGShocker and myself just last week met with Gary from All American Air Conditioning 928-855-4549 at Acoma & Mc Culloch, he came out within 20 minutes of original call and had a new 5 ton unit installed within the week. Our old unit would not let the house get below 85 during the day.... cooler than outside, but not much. Although about midnight it would cool to about 78. Shocker and our floor installers are enjoying working in the house now that it is cool :)

[Tom Brown]

What hasn't Tom done? :idea: :mix:
I'm sure if I were to enter politics, some pictures from my drinking days would surface that would surprise us all.

[ROZ]

Oh, uh, I don't know!
What about being tied to a giant Sequoia, and beaten with warm squash by jack Mormons, disquised as Amish? :D I'm thinking he has done that one already.... Jack Daniels was partly to blame :D

[BoatPI]

Sounds like a few runs up and down the roof with a well supplied ice down of beers ended well. Like I said, this icing condition is not uncommom during monsoon season. Having experienced myself the 74 degree thremostat setting and the fan in the off position threw it over the edge.
I think he may have a few registers closed too.
Oh, I am just a layman on this stuff, but my father was a superintendent at Johnson Controls in LA for 30 years. One of his last assignments was supervising the HVAC portion during construction of the Miller Brewery in Fontana, CA.
Free beer too I beleive.

[Tom Brown]

I'm thinking he has done that one already.... Jack Daniels was partly to blame :D
I believe you and Ray are thinking back to my crack cocaine phase. :D

[TheLurker]

the big question is how many beers has he been able to cool off and dispose of so far!!!!!
Followed this thread and learned a little about AC trouble shooting thanks guys.
I also like the fact that Gramps knows what the priorities are.

[Tinkerer]

So how dirty was the air filter and be honest.
A very dirty filter will usually cause the evaporator coil to freeze up.
Once the coil freezes up the airflow will stop.

[JetBoatRich]

Looks like we may have a A/C problem and may need a tech to come out :boxingguy
Evereything turns on, but no cold air :sqeyes:

[MRS FLYIN VEE]

Looks like we may have a A/C problem and may need a tech to come out :boxingguy
Evereything turns on, but no cold air :sqeyes:
I wish I knew about air.. but there is a fuse in the unit .. :shift:

[JetBoatRich]

I wish I knew about air.. but there is a fuse in the unit .. :shift:
I am headed up North in the morning, so it wil have to wait :mad:
But all the fuses did check out, the compressor turns on, etc.
Thanks

[MRS FLYIN VEE]

I am headed up North in the morning, so it wil have to wait :mad:
But all the fuses did check out, the compressor turns on, etc.
Thanks
your welcome.. :shift:

[LASERRAY]

Looks like we may have a A/C problem and may need a tech to come out :boxingguy
Evereything turns on, but no cold air :sqeyes:
Sounds like your possibly low on refrigerant Rich. :(

[JetBoatRich]

Sounds like your possibly low on refrigerant Rich. :(
The unit is 9 years old and never had a problem, so no complaints. You may be right with what is teh problem, or it could be tired :yuk: