View Full Version : Central A/C unit problems - help!
Byron
07-02-2012, 08:16 AM
(I don't know jack about HVAC, so I'm sure I'll use some incorrect terminology.)
My central A/C has recently been unable to cool my house sufficiently. It is not 100% dead, but my house is hot enough that I've been staying with friends.
The symptoms originally started on Saturday, the morning after we had a very nasty storm here. I don't see any physical damage to my outdoor unit, so I think the timing is most likely just coincidence, but I mention it just in case.
The unit runs, but the air that comes out of the vents is only slightly cooler than room temp, and as the day wears on, the house steadily rises in temp. As you can see in the pictures below, there is ice heavily forming on my unit, even in outdoor temps of >95 and the sun on it. From my online searches, I see a million different theories about why this could happen: leaks (seems most likely), filters, refrigerant levels, blowers, coils, evaporators....... and obviously I don't have the technical knowledge to identify these issues on my own.
I have a service call for tomorrow morning, but I'm hoping someone with experience might offer me some advice.
Please take a look at the below pics and let me know if anything immediately jumps out at you. If there are things I can check on my own, I'd be happy to. My knowledge in this area is quite limited, but if there's a DIY fix that can be done with online guides, I'm happy to try. Basically I'm just trying to avoid being charged $200 for something I could do myself for $50.
If the answer is, "You shouldn't be touching it; just wait for the tech," that's fine too. I just don't want to pay more than I have to, so any advice is appreciated.
http://byrong.com/AC/ac1.jpg
http://byrong.com/AC/ac2.jpg
http://byrong.com/AC/ac3.jpg
http://byrong.com/AC/ac4.jpg
Environmentally sound refrigerant? I'm hoping that doesn't just mean "more expensive to fix"
P.S. - the appointment I have is through BGE Home, simply because everyone else I contacted was either closed Sunday or quoting me appointments for many days later. If this is a bad choice to make, I'd appreciate any specific recommendations you might have for the Baltimore MD area.
Thanks!
(Also, in case it is relevant, the home was built around 2005 and I bought it in 2009. This is the original unit that came with the house.)
It is very likely you are low on refrigerant and the ice forming is a typical sign. Shut the unit down and wait for a tech to arrive. Hopefully you caught it early enough and the compressor is OK.
Ice is a common sign for a few things, IME - it's usually an air flow problem (dirty filter or coil) and/or low refrigerant.
Once the ice forms, it starts a vicious cycle of making more ice and further reducing the performance so it can make more ice.
ford.304
07-02-2012, 09:13 AM
I'll just echo what others have said. Ice is bad. If you ever notice it starting to form ice, stop running it immediately, double check the filters and vents around the coils to make sure they aren't clogged, and call a repair dude to add refrigerant.
You should honestly get the refrigerant levels checked every year, or at least every other year. Being a little low on it costs you big on electric bills. Being too low will damage the unit.
Since it is a puron system (R410), it will have a TXV metering device, which keeps the evap coil above freezing unless something else is going on.
I agree with JV, you likely have an airflow issue somewhere.
rob_s
07-02-2012, 09:46 AM
I'll just echo what others have said. Ice is bad. If you ever notice it starting to form ice, stop running it immediately, double check the filters and vents around the coils to make sure they aren't clogged, and call a repair dude to add refrigerant.
You should honestly get the refrigerant levels checked every year, or at least every other year. Being a little low on it costs you big on electric bills. Being too low will damage the unit.
Pretty much any time you get little to no cooling, you should just shut the thing off. The system will generally just keep running and running because the thermostat isn't registering the target temperature. No good for electric bills, no good for the equipment.
It could be refrigerant, it could also be that your compressor or compressor motor is shot. Generally not an overly expensive fix.
How old is the total package? It should have a tag with a date on the side.
Byron
07-02-2012, 10:04 AM
Thank you everyone for the advice and help so far! The unit is indeed off now, so hopefully it's not damaged too bad.
Regarding air-flow/air-filter (and I'm really showing my ignorance here, I know) are you guys just referring to the user-replaceable air filter that's indoors, in my main utility room? If that's what you mean, I just put a new filter in a few months back. Or is there a filter in the unit itself that you're referring to?
How old is the total package? It should have a tag with a date on the side.
I'm not home right now to check for sure, but I can tell you this much:
The home was built in 2005, and this is the A/C unit that came with it (same one that all my neighbors have). I purchased the home in 2009. I don't know if the previous owner ever had to service the unit, but this is the first time I've had any problems with it. With that said, I've never had the levels checked before, as it sounds like I should have :(
Since it is a puron system (R410), it will have a TXV metering device, which keeps the evap coil above freezing unless something else is going on.
I agree with JV, you likely have an airflow issue somewhere.
Does the puron system present any complexities that I need to notify the tech of ahead of time? Or is it standard enough that they'll have the proper materials with them?
Regarding air-flow/air-filter (and I'm really showing my ignorance here, I know) are you guys just referring to the user-replaceable air filter that's indoors, in my main utility room? If that's what you mean, I just put a new filter in a few months back. Or is there a filter in the unit itself that you're referring to?That's just one piece. Your condensing coil/unit (outside) and evaporator coil (inside) also need to be cleaned periodically.
Or is it standard enough that they'll have the proper materials with them?Your tech should be fine, no notice is necessary.
ford.304
07-02-2012, 10:23 AM
Regarding air-flow/air-filter (and I'm really showing my ignorance here, I know) are you guys just referring to the user-replaceable air filter that's indoors, in my main utility room? If that's what you mean, I just put a new filter in a few months back. Or is there a filter in the unit itself that you're referring to?
If it's one of the big box filters, it should be replaced about every 3 months. If it's one of the thin 1" filters it should be replaced monthly.
http://www.howstuffworks.com/how-to-maintain-an-air-conditioner.htm
cclaxton
07-02-2012, 10:50 AM
It is likely that you don't have enough gas in the system. It is also likely that the coils inside the air handler are icing up as well. This is usually an indication of a gas leak or not enough gas. Call your A/C contractor and have him look at it. BTW, if it is a leak, ask if they will add leak sealant rather than an expensive replacement or repair job. Leak sealant repaired mine just fine....but A/C companies would rather sell you expensive repair work or a new unit....buyer beware.
CC
Byron
07-02-2012, 10:55 AM
Fantastic info. Thanks again, guys! Becoming better educated about this definitely gives me better peace of mind. I'll go thoroughly read the HowStuffWorks article.
ask if they will add leak sealantI would suggest that you fix the leak, rather than try to try the band-aid approach.
Does the puron system present any complexities that I need to notify the tech of ahead of time? Or is it standard enough that they'll have the proper materials with them?
Nope. R410a is an azeotropic mixture, but the tech will know what to do with it.
FYI - AC sealant is just like radiator sealant. Bad stuff all around. Don't use it. Bigger problems will result 99.999999% of the time.
Cheers!
David Armstrong
07-02-2012, 01:27 PM
I'm not home right now to check for sure, but I can tell you this much:
The home was built in 2005, and this is the A/C unit that came with it (same one that all my neighbors have). I purchased the home in 2009. I don't know if the previous owner ever had to service the unit, but this is the first time I've had any problems with it. With that said, I've never had the levels checked before, as it sounds like I should have
Twice a year, once in the spring to get ready for summer, once in the fall to get ready for winter. It doesn't cost much, and a little maintenance really goes a long way with these systems. Make sure all the drains are working right, the oil and gas levels are good, get a general cleaning and inspection.
NickA
07-02-2012, 01:40 PM
Sounds like you've got it figured out but I'll throw this in: until you mentioned the ice your situation sounded exactly like mine a few years ago, it was even after a big storm. Fan was running, but the air wasn't cool. The answer turned out to be the last thing I checked- the circuit breaker for the outside unit. Pretty ironic for a guy who's been in the electrical business most of his adult life :) I felt like the guy in Sling Blade when Billy Bob checks out his mower and says "It ain't got no gas in it. "
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cclaxton
07-02-2012, 06:33 PM
Nope. R410a is an azeotropic mixture, but the tech will know what to do with it.
FYI - AC sealant is just like radiator sealant. Bad stuff all around. Don't use it. Bigger problems will result 99.999999% of the time.
Cheers!
Actually its not "just like radiator sealant"....at all. It is specially formulated specially for this application. It does not cause internal damage. My AC mechanic put it in two years ago.....been running cool ever since. I am a fan....cost me $75 for the service and $30 for the sealant. The repair estimate was $325-500...saved me lots.
Just have your AC mechanic do the job and have him use quality stuff.
CC
Sounds like you've got it figured out but I'll throw this in: until you mentioned the ice your situation sounded exactly like mine a few years ago, it was even after a big storm. Fan was running, but the air wasn't cool. The answer turned out to be the last thing I checked- the circuit breaker for the outside unit. Pretty ironic for a guy who's been in the electrical business most of his adult life :) I felt like the guy in Sling Blade when Billy Bob checks out his mower and says "It ain't got no gas in it. "
Sent from my PC36100 using Tapatalk 2
this situation happened to me as well.
the ice indicates it may be a leak somewhere, as would a low coolant situation. my repair guy (also a bryant system btw) said that I definitely shouldn't be low on coolant unless I had a leak. My system is from 2001.
Actually its not "just like radiator sealant"....at all. It is specially formulated specially for this application. It does not cause internal damage. My AC mechanic put it in two years ago.....been running cool ever since. I am a fan....cost me $75 for the service and $30 for the sealant. The repair estimate was $325-500...saved me lots.
Just have your AC mechanic do the job and have him use quality stuff.
CC
Please enlighten me. The difference is what?
It is designed to be soluble in the appropriate refrigerant (it uses refrigerant as a carrier). Like radiator sealant in antifreeze.
It is designed to harden and thus "seal" when "leaked out." Like radiator sealant.
It never forms a good bond when it does this because of the oil carried by the refrigerant (ever see a glue adhere when the part was coated in oil?). Like radiator sealant and slow to evaporate glycol.
With age, it can form blockages in smaller passages and potentially gum up the compressor.
It does not cause internal damage. On what information are you basing this statement? Do you have other experience with these types of products, more than just writing a check as a homeowner?
Byron
07-03-2012, 10:51 AM
I ended up very lucky: it was indeed just an air-flow problem that was exacerbated by our recent heat (and therefore extra work of the unit). The tech serviced everything, checked levels, etc. There were no leaks detected, and after servicing the unit it immediately started performing like new. Cost was minimal, and I signed up for a cheap service plan that will give me free annual servicing, plus other benefits should I encounter a worse problem down the line.
Thanks again to everyone for your advice.
LittleLebowski
07-03-2012, 10:54 AM
Glad you're good; this heat is no joke. Now that I have a spare window AC, I feel much better prepared.
Byron
07-03-2012, 11:03 AM
Glad you're good; this heat is no joke. Now that I have a spare window AC, I feel much better prepared.
Thanks man. What's been crazy about this heat is how persistent it is. Even after these storms whip through, it seems the temp just jumps back up immediately. Of course, I'm sure our friends in the Western states are looking at us in contempt :eek:
I would love to get a spare window AC: I think it's definitely a good idea (especially for people who have pets/kids to worry about). Unfortunately my HOA would come into my home and slit my throat in my sleep if I tried such a thing. But I'm not really complaining: I've never had a problem with my HOA and I deeply appreciate the various services provided (like amazing snow-removal)
Dropkick
07-03-2012, 12:07 PM
Thanks man. What's been crazy about this heat is how persistent it is. Even after these storms whip through, it seems the temp just jumps back up immediately. Of course, I'm sure our friends in the Western states are looking at us in contempt :eek:
I would love to get a spare window AC: I think it's definitely a good idea (especially for people who have pets/kids to worry about). Unfortunately my HOA would come into my home and slit my throat in my sleep if I tried such a thing. But I'm not really complaining: I've never had a problem with my HOA and I deeply appreciate the various services provided (like amazing snow-removal)
Well, there is indoor floor standing units too... But should generally be avoided like the plague. I've never heard of, or seen, any being very effective.
LittleLebowski
07-03-2012, 12:20 PM
I'd absolutely get an indoor unit rather than have nothing in this heat. At least I would if I had a spouse in the house. Single men can usually tolerate a bit more.......
Slavex
07-04-2012, 07:12 AM
Ductless splits are the way to go if you're serious. Individual room control, heating and cooling. The portable rolling units work great if you get the right size one. It still needs to be vented outside though, and most will also draw fresh air from outside rather than drawing from the room they are in.
I'm generally ho-hum on window units for our area, forgetting about HOA issues. Because they often work so hard, and sweat internally (which introduces more moisture), coupled with poor sealing around the units - they do a terrible job at controlling humidity. Reducing the humidity in a room is one of the key points to making it FEEL cooler, even if there isn't a great temperature difference.
A MiniSplit is fine, just be careful with NOT over-sizing the unit or they will short cycle (further reducing the efficiency and not controlling the humidity), and their placement is pretty important.
LittleLebowski
07-05-2012, 06:19 AM
I only have a window unit for emergencies.
Tamara
07-05-2012, 06:37 AM
What's been crazy about this heat is how persistent it is. Even after these storms whip through, it seems the temp just jumps back up immediately. Of course, I'm sure our friends in the Western states are looking at us in contempt :eek:
Only the ignernt ones. I'll take 106 dry degrees in Vegas over 90 degrees and 70+% relative humidity any day of the week and twicet on Sunday.
Glad you got your A/C probs solved; the evaporator coils froze up here at Roseholme Cottage last summer, and now my roomie and I get jumpy any time it feels even a little warm in the house and run to the nearest A/C vent to make sure everything's normal... :o
jstyer
07-05-2012, 06:54 AM
Only the ignernt ones. I'll take 106 dry degrees in Vegas over 90 degrees and 70+% relative humidity any day of the week and twicet on Sunday.
So so true...
What's been crazy about this heat is how persistent it is. Even after these storms whip through, it seems the temp just jumps back up immediately. Of course, I'm sure our friends in the Western states are looking at us in contempt :eek:
Only the ignernt ones. I'll take 106 dry degrees in Vegas over 90 degrees and 70+% relative humidity any day of the week and twicet on Sunday.
...unless by "friends in western states" he meant folks like my two colleagues whose houses were razed outside Co. Springs... :eek:
Only the ignernt ones. I'll take 106 dry degrees in Vegas over 90 degrees and 70+% relative humidity any day of the week and twicet on Sunday.
Glad you got your A/C probs solved; the evaporator coils froze up here at Roseholme Cottage last summer, and now my roomie and I get jumpy any time it feels even a little warm in the house and run to the nearest A/C vent to make sure everything's normal... :o
When I pulled into Tucson this evening last, humidity was hovering at ~87%
Blech.
Tamara
07-05-2012, 09:18 AM
...unless by "friends in western states" he meant folks like my two colleagues whose houses were razed outside Co. Springs... :eek:
Well, yeah, fourteen hundred degrees is pretty hot, no matter how dry it is.
When I pulled into Tucson this evening last, humidity was hovering at ~87%
That is miserable. Humans are air-cooled and not evolved to survive in those conditions.
When I was commuting on a motorcycle a hundred miles a day in Atlanta traffic, I was scrupulous about wearing safety gear. The only time I'd ditch the leather jacket and ride in my tee shirt was on "90/90" days, because I figured I was in more danger of passing out and falling off the bike in bumper-to-bumper traffic than I was of getting in a regular wreck-type wreck.
I'd absolutely get an indoor unit rather than have nothing in this heat. At least I would if I had a spouse in the house. Single men can usually tolerate a bit more.......
$$$$ spent on AC = Less $$$$ spent on guns, bikes, and dive gear.
Single men have more clear priorities ;)
David Armstrong
07-11-2012, 11:55 AM
An addendum to an older thread, but something came up yesterday that I thought fit into this discussion. In addition to the delights of having a generator, I have found that some version of a battery back-up/surge protector is really nice. Got to use a surge protector anyway, and for a little more money you can get one that conditions the power, provides protection, and gives you some extra time to take care of things when the electricity has trouble. Instead of losing everything you have a few minutes to shut everything down the way it is supposed to shut down, save things as needed, and so on. I have one on my home theater system and my computer setup.
LittleLebowski
07-11-2012, 12:14 PM
I don't think a UPS for an A/C is a realistic proposition. Better a generator.
David Armstrong
07-11-2012, 04:30 PM
I don't think a UPS for an A/C is a realistic proposition. Better a generator.
Me neither. Sorry if that wasn't clear. The UPS helps to keep some things going while your generator kicks into action, during brown-outs, areas where the electricity flickers a bit, and so on. It is certainly not a substitute for a generator.
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