Hvac refrigerant

[trekrok]

AC wasn't cooling much so I did my annual wash the dryer lint off the condenser routine. It was about half covered, so I expected it to get better. It hasn't. Last few days it runs non- stop and house is in the mid 80s.

I tried my 10 year old harbor freight gauges and couldn't get any reading. So, either gauges are screwed or system is empty. I'm thinking the latter is likely since I didn't get even a wisp of refrigerant when I connected the gauges.

System is probably 2008 or so, but definitely before 2010.

I guess that's the long winded call to see if we have any HVAC guys that would take a look?

 

[ShaneP]

Can you tell if the compressor is running? Do you feel any heat coming off the top of the unit where the fan discharges? If you have an amp clamp, read amps on the compressor vs RLA on the unit name tag. If it's drawing low amps, it's low on refrigerant. Most all modern units will have a low pressure safety that will keep the unit from energizing if the charge gets to low. The compressor is cooled by the returning refrigerant vapor, so without the cool vapor coming back it will overheat and burn out. The low pressure will usually stop the entire unit, so the fan would not be running either.

Another thing you can do is feel the lines at the unit. The smaller line should be warm to the touch, and the larger line should be "beer can" cold if working properly.

 

[trekrok]

Can you tell if the compressor is running? Do you feel any heat coming off the top of the unit where the fan discharges? If you have an amp clamp, read amps on the compressor vs RLA on the unit name tag. If it's drawing low amps, it's low on refrigerant. Most all modern units will have a low pressure safety that will keep the unit from energizing if the charge gets to low. The compressor is cooled by the returning refrigerant vapor, so without the cool vapor coming back it will overheat and burn out. The low pressure will usually stop the entire unit, so the fan would not be running either.

Another thing you can do is feel the lines at the unit. The smaller line should be warm to the touch, and the larger line should be "beer can" cold if working properly.

Compressor has been running. The low pressure line is cool but not beer can cold for sure. It's blowing warmish air at the condenser. I just hosed off the lint when I did it a few days ago, so I just now used compressed air from inside out on the condenser and blew some dust out, but I doubt enough to make a difference.

Just turned it back on and air in the house is still barely cool out of the register, so if it helped at all its minimal.

 

[Bahick71]

Have you checked your filter inside? or have you checked your A coils to see if they are dirty
Either of those problems will cause low volume of air, and it not feel as cool, because it will
bypass the coils and not chilled. A dirty filter will also cause your A coils to get plugged up
because the air will bypass the filter.

 

[trekrok]

Have you checked your filter inside? or have you checked your A coils to see if they are dirty
Either of those problems will cause low volume of air, and it not feel as cool, because it will
bypass the coils and not chilled. A dirty filter will also cause your A coils to get plugged up
because the air will bypass the filter.

I changed the filters a few days ago, but they probably didn't need it. I haven't checked the A coils - that on the inside unit I guess?

 

[TinkerTanker]

That line should be beer can cold. My vote is low refrigerant. If you want to do it yourself, you can't do it legally so you gotta cover your eye and wear your pirate hat. If you don't want to do it yourself, call the HVAC guy and he'll charge it up for you, tell you there's a hole in it. If you're lucky it's at the gauge connections, if you're not it's in the A coil. If you swear too much and God took it personal this year it's in the compressor.

 

[saddlebum]

That line should be beer can cold.

not necessarily

 

[trekrok]

I pulled the front off the A coil and they weren't terrible but brushed some stuff off of them. The drain was plugged and unit was overflowing water and some running out of closet. I opened up the drain. Can't imagine I helped the cooling much, but turned it back on for a while. Went from 83 to 80 in about an hour and half. But I'll be surprised if the trend continues when it warms up outside.

 

[SlugSlinger]

See if there is a leak at the schrader valves. Spray some soapy water on the valves. That’s a common place to leak. Get some brass caps to help with the leak or have the valves replaced.

@eaglerjs is a great resource of information.

 

[SlugSlinger]

I pulled the front off the A coil and they weren't terrible but brushed some stuff off of them. The drain was plugged and unit was overflowing water and some running out of closet. I opened up the drain. Can't imagine I helped the cooling much, but turned it back on for a while. Went from 83 to 80 in about an hour and half. But I'll be surprised if the trend continues when it warms up outside.

Is there a shutoff switch in the pan under the unit? I don’t know, but it’s probably code to have a switch to shut down the AC if the pan fills with water.