Hello Michelle, nice summary of the previous posts here (
) ! Sorry to hear it's still not working.
Given that you said *Blew air through the drain lines at upstairs unit - I take it to mean that you have a two-zone system controlled by two thermostats and a zone control board such as Lennox Harmony, one air handler with evaporation coil located upstairs and one 3 ton outside unit? How warm is your climate? I don't remember you mentioning in the previous posts where you live.
It sounds like the compressor is overheating after an hour or so and its safety device shuts it off. There could be a host of reasons it may overheat, including lack of refrigerant charge, plugged up lines, bad metering devices, lack of cooling and more. Perhaps a few more questions could help to narrow it down:
Does it shut down before getting the house to the the zones' set temperature or does it bring it down fine but on the next call for cool does not turn on?Â Does the fan start together with the compressor and works the same time or shuts down before the compressor? Did you buy exact same replacement capacitor?
Been working on this all week and to make it easier - going to post consolidated question with what has been tried to date in hopes of help.
Lennox 13ACD-036-230-02 - 3 ton unit with 1995 sq foot house with 2 thermostats (1 upstairs/1 downstairs) House was bought new in November 2007.
About 3 weeks ago, fan stopped turning which blew hot air in house. Unit was hot to touch. Disconnected all power and tried to test power coming in to unit and did nothing in terms of repair and it started up when turned back on without any issue. Acted as if possible loose connection coming in to unit.
Last week, stopped again. Turned off all power, waited several hours and turned back on. Worked fine for few days and stopped again.
Turned off all power and waited few hours. Turned on and worked for very short time. Fan stopped but could be manually engaged by putting something through opening on top and pushing blade. Unit also made really odd noise this time. Below is what has been done since:
*Filters are changed on monthly basis normally but this last month, they were much dirtier than normal.
*Opened top of unit and cleaned the fin area - was dirty and dusty with cobwebs. Some of the edges of the fins are bent like where they meet with the outer part of the top of unit.
*Inside top of unit had cobwebs and dust inside also. Wiped out.
*Uncertain how to test capacitor correctly so changed it out today. Ran fine at start up afterwards and then stopped again within an hour or hour and half. At time of changing capacitor, used can of coil cleaner and cleaned coils as well.
*Blew air through the drain lines at upstairs unit
Hi! Â Was not sure I would get the same responding person as I had been working with but am so thankful I have. Â You have been instrumental in getting me this far!! Â
Yes, I have a "zoned" AC which I still do not really grasp the concept of just yet but do know I have one inside unit and one outside unit and 2 thermostats.
The capacitor I replaced the original one with most likely was different brand (got it from Grainger Supply) but it is same size. Â In fact, I saw another post where someone had similar problems and used the one from Grainger, which is how I knew which one to get. Â
The outside fan will stop running well before house has cooled down but you have to remember going several days without AC in Austin Texas (in the high 90's, low 100's right now) the inside of house would take several hours to cool down once operational again. Â
The fan would stop turning and unit would feel hot to touch when it first began this problem (like really noticed that last week). Â Now, I am so paranoid of it stopping that I check it every few minutes trying to make sure I catch it asap and turn off power in hopes of not ruining something else. Â
One thing that bears mentioning that I hadn't before is that the house went without electricity for 8 months last year (like January 2011-August 2011) but had no problems when turned on power and appliances. Â
I also had the local weatherization program reps come out and check insulation in attic and they said it was fine and they were supposed to have sealed any cracks, etc but truth is they did a crappy job but I can't see anything major that would hurt unit.
I have 2 drains running outside my house. Â One from upstairs it looks like that is just above one of the windows in the living room which is on the back side of the house. Â The second one is on the left side of house close to the ground (I put rose garden here so that water helps with the watering of those). Â The one on back of house had some grass stuff hanging out but did not appear blocked. Â One on side of house has not shown problems with dripping I have noticed.
I read to test the fan motor, you disconnect the motor from capacitor and connect black probe on hot connection and red probe on the common one. Â The meter we have doesn't have clips but needle like things so had to use manual clips to keep in place. Â Turned power on and when compressor finally kicked in showed read out of 3.7 on meter. Â Tried again with different meter to ensure was using alternating current and got no reading but person helping me may not know what they are doing. Â
I have some concerns about condition of outside unit also. Â There seems to be some areas on the outer part that have been damaged, one showing some melting to inner part. Â Then, there are the fins and being bent I mentioned before. Â Also, on inside of the unit, there is a line that seems to be damaged. Â I have taken photos and will download and post in separate reply.
Close up of the fins. Â The sun kept messing up the pictures so will try to take another one tomorrow. Â
There are 2 rows it looks like to me and the outer is definitely worse than the inner.
Towards middle of picture you will see the "line" on the inside of unit I mentioned above
Missing area on outer part of the outside unit mentioned above
Different angle of photo below trying to capture the small melted area mentioned
second spot on outside of unit I mentioned
First 4 pictures are of the original capacitor. Â Last picture is the box of the one replaced it with today.
Â The new capacitor has the same value as the old, so no problem here. I am assuming you were very careful putting the wires back connecting them to the same terminals on the capacitor.
Â Hi again Michelle, just wanted to say that the pictures you posted don't show any unusually bad damage, nothing you would not see on a 5 years old condenser coil being out there with lawn mowers and other stuff going on around it. The spot you call "melting" is hard to see on the picture but it looks like it has just suffered a harder kick than others and the aluminum fins have been compressed more, but it's the same kind of damage, commonly inflicted by lawn mowers kicking up some pebbles, and still does not look too bad or too extensive.
Your description of testing a live motor made my hair (what's left of it) stand up. In the interest of saving your life and good health as well as that of the person helping you, please please call a Lennox ceritifed HVAC tech and have them check the system out. By now you have made far more effort than an average consumer would in trying to fix an air conditioner. What you have observed and done so far will be very helpful for the subsequent professional repair, will make it quicker and cheaper. But I sense that we are approaching a territory where using proper tools and very specialized equipment is going to be essential for making this A/C run again.
More to the point: when you mentioned the two drains, it has to mean that this is a rather unusual setup whereby one condenser unit outside feeds two separate evaporation coils, each with its own air handler, I presume, controlled by two separate thermostats, and not a multi-zone control system like the Lennox Harmony I suggested before. This setup is not unheard of but it is not common, very complicated and takes quite a bit of work and experience to install properly and tune up. This is due to the specifics of the refrigerant flow in the system, longer refrigerant lines and their different lengths and other issues related to proper distribution of refrigerant in such system.
As much as any work on the sealed part of any A/C system is not a DIY job (and prohibited by law due to concerns of refrigerant release into the atmosphere), your particular setup is taking it to a higher complexity level yet.
One thing you can do before a pro gets involved is to locate the two indoor evaporation coils and their respective air handlers and verify that none of those is freezing up while the compressor runs and none has air flow to it obstructed in any way, such as the coil itself being dirty or its air return filters etc. Also, I don't remember if you've mentioned whether the air flows from the registers of both zones (upstairs and down) normally when the compressor does run.Â If one of them differs considerably from the other in terms of available air flow, it's an issue that needs to be addressed.
If you don't find anything wrong with both indoor coils, then the only reasonable thing left to do is to callÂ an HVAC tech. Otherwise fix the issue and let the A/C run longer to see if your compressor overheating problem clears.