To add to the story that others have been kind enough to participate in, my 2nd floor system is no longer working. Oh, the blower is making its usual humming noise as if it is blowing, but almost no air if felt at the supply registers.
Conversely, the 1st floor unit is running, too, but there is heat being blown off the condensor unit via its fan. Also, I feel cool air blowing through the supply registers. Its 76ºF and dropping on the 1st floor.
Earlier today I noticed no heat coming off of the outside condenser unit while the unit was on (blowing). This evening the 2nd floor temp is 85ºF, which is the exact temp that it is outside. In the end, I simply shut it off since no heat is being removed.
If the blower is fine, what about the condensor unit? If its fan is blowing, can it do this with a frozen compressor? So, much for the detectorless HVAC contractor. “its operating within design.”
I did enjoy the 2 nights out of 13 past nights that I got to sleep in my own bed. Now it will be 2 in 14, and 15, maybe 20 before this gets resolved.
Edited 8/18/2007 9:34 pm ET by NeoNuke
Replies
turn the top unit off, it sound like its ice up and blocking the air flow. dirty filter low on freon is usually the cause of ice up coil
.
Haga su trabajo de fricken
No air at all, or no cold air?? Your post elsewhere didn't say you were getting no air. If it's no air then:
1) Clogged filter
2) Fan belt broken (though this probably isn't a belt drive unit)
3) A coil iced up, either due to clogged filter or due to low freon.
If you're getting air, it just isn't cold, then see the other thread about resetting the overpressure cutout switch on the condenser unit.
Its not the filter. I'll check it again, but it was fine last weekend. I do not know if I am getting air or not. I wasn't sure, because I didn't know how hard air should be felt from a supply register if its the same as ambient temp.
I guess I'll be yelling at HVAC #1 for not catching what they could have caught provided the idiot brought his leak detector.
I know you think a leak detector is the end all to all your problems... but it just ain't so...
if your a/c has a set of guages and can read them... and after the system has been in operation... 1yr.... 3yrs whatever... chances are you will have a loss of freon... maybe it was never charged right... things wear and things leak... can a system be 100% leakproof... ? yes... but 99.9% might be the very high end of average... even at that you will require freon at some point...
simple test... while the unit (blower) is running... remove the filter... if it just slides out and you feel no suction... and you know the blower is running then you have a blocked coil... could be ice? could be duct insulation found it's way to block your coil...
I assume at this point the unit has been turned off so there shouldn't be any ice...
simple check for low freon is the lines closest to your outside unit... this is usually where ice will form first.. a litlle low... ice on the line... alot low... feel the liness... if they are both warm... alot low
p
simple check for low freon is the lines closest to your outside unit... this is usually where ice will form first.. a litlle low... ice on the line... alot low... feel the liness... if they are both warm... alot low
Another possibility is bad valves on the compressor. The gauges will show a "low freon" condition, yet no amount of refrigerant added to the system will bring the pressures (especially suction) up to normal. The subcooling and superheat will never be correct, either.
There could be icing on the suction line because the pressure is so low.
Because the system is in an attic, and possibly was never charged right, this is a possibility.
No way to know for sure without gauges and a couple of thermocouples.
Yeah, could be that the system was never properly evacuated and charged, and there's moisture in it.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Morning all. This morning I got up and switched the thermostat from Auto to Fan while leaving the system off (set from Cool to Off last night). I then gave it about 15-20 seconds and walked over to a supply register and could feel air coming out of it.
I then switched the thermostat from Off to Cool, gave it a couple of minutes and felt cool air (not cold) coming out of it. Went outside and felt slightly warm air being blown off of the condensor unit.
I gather this to mean the compressor and fan in the condensor unit is probably working to some degree, and that what everyone was concluding as an iced over evaporator coil may be the case. I just read the other tests that some have asked me to do, which is run the fan and see if there is resistance (drag on the filter material from flowing air), but haven't checked that yet. Do it now ...
There was definately some drag on the filter this morning. I shut the unit and removed the filter. It wasn't as dirty as the last one (about mid course). I replaced the filter anyway. What dust was on the filter was dry, not moist or wet. It has lowered the temp upstairs since I turned the unit back on at 8AM this morning, but I think in the next hour its going to go belly up--I'm going to shut it off again.
There are no gauges that I can find on any component.
you low on freon.Haga su trabajo de fricken
Or there's a restriction in the ductwork somewhere.
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
Low on Freon is the obvious assumption.
However, there is no way to know what is going on until some gauges and thermocouples are in place.
I worked on a unit that showed "low on Freon" symptoms, and the total factory charge was 6# of R22.
I pulled 12# out of it.
Compressor valves are bad, and the last guy that worked on it thought adding Freon until the pressure came up would fix it.
The unit still cools, and the suction line will frost up. As long as the homeowners are happy with the performance and electric bill it stays.
If a leak can't be found on Nukes system, I would suspect bad valves.
If a leak is found at the service ports or king valves, I would repair, evacuate and weigh in a factory charge to start.
Did it again, today. This time the wife wondered what the heck all the rumbling noise was. She thought someone was doing yard work. Nope. It was the condensor unit's compressor and the blower fan in the attic.
My wife had been gone over the weekend, worked until midnight on Monday and Tuesday, and I had not gotten a chance to relate to her this past weekend's experience. Thus, she was never warned, and today the unit driven into the ground.
So, on her own she shut the unit off, but I doubt the compressor is good if it was making rumbling noises. Moisture probably got into the line, froze up and ruined the seals on the compressor. Nice. I am taking tomorrow as another HVAC person is coming by in the afternoon.
I miss the north.
Well, it's probably shot now.
If it was low on refrigerant, that also means that oil is not being returned to the compressor, and the compressor is not being cooled by the refrigerant.
Hate to say it, but you would have been better off getting a couple of cheap window shakers and shutting it off (as others have suggested) until someone could have evaluated the system.
Now, if the compressor lunched, there is junk circulating in the linesets which are buried within the walls, and junk trapped in the evaporator coil. Proper service procedures (lotsa luck here) must be followed (a suction line drier, and return visits to check pressures and remove it) in order to ensure the best service life from new components. A "run and burn" compressor failure is the worst.
If the replacement isn't done right, that new compressor acts as the filter :) As you might imagine, that isn't a good thing.
Topping things off, the new 13 SEER equipment usually uses a larger diameter lineset than 10 SEER equipment. HVAC hacks will tell you that keeping the old lineset or evaporator coil is just fine....
There are only 2 ways that moisture can get into the system. Either operating the system in a situation where the line pressure goes below atmospheric, allowing outside air to be drawn into the system through a leak, or, that moisture was installed for you at initial start up (ie: no vacuum pump was used- common on most residential work).
Lots of luck...
Edited 8/22/2007 11:00 pm ET by danski0224
As pointed out, if the blower motor is on, yet there is no airflow from the registers, then there is a blockage somewhere.
If the AC is on, then your coil is probably a block of ice.
Turn off the AC. It is also a good idea to cut the power to the furnace because if there is a lot of ice, the runoff could do some damage to the equipment.