Air leak and cooling problems with A/C and furnace


  #1  
Old 06-26-24, 06:24 PM
F
Member
Thread Starter
Join Date: Aug 2005
Location: USA
Posts: 377
Received 0 Upvotes on 0 Posts
Air leak and cooling problems with A/C and furnace

Trane XR95 furnace, with a Carrier evap coil. I just noticed that the spot where the drainage pipe comes out of the coil is leaking a lot of air. I attached a photo of the area in question. Since the installers did an overall horrible installation, I'm wondering if there should be something there to prevent the air from escaping, and if so, what?

Also, I have a very old A/C unit that I need to replace soon. When the system starts, the filter drier is really hot, and the A/C blows cool (not cold) air. After a little while, the drier cools down, and the A/C output gets warmer. Is this due to the A/C unit being on its last legs, or low on freon, or is it a symptom of a different problem? Thanks!
 

Last edited by flukeslapper; 06-26-24 at 06:29 PM. Reason: additional question added
  #2  
Old 06-26-24, 07:39 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,968
Received 4,149 Upvotes on 3,726 Posts
It is not uncommon for air to leak there.
I just put in a Goodman furnace and has several air leaks including at the refrigerant lines mounting plate and around the drain area.

You can plug it but it needs to remain removable to get to the coil.
Sponge rubber/foam makes a good filler.

The filter/drier on the small line outside will get warm.
The larger (insulated) line should be ice cold.
How old is old ?

My Rheem was 35 years old. The compressor finally gave up.
Never added any refrigerant to the system.

 
  #3  
Old 06-27-24, 08:19 PM
F
Member
Thread Starter
Join Date: Aug 2005
Location: USA
Posts: 377
Received 0 Upvotes on 0 Posts
Thanks for the info on the leakage. As for the filter/drier, I don't see one outside. The only one I'm aware of sits to the right of the pvc pipe in the photo, in front of the coil's access panel. Is the drier starting out really hot, and turning cooler after 10 minutes or so behavior normal? The Bryant A/C unit is around 20 years old. I added a hard-start capacitor to it years ago. Very long story short, the contractors who installed the furnace and ductwork yanked the A/C unit and tossed it into their truck. I stupidly told them (can't help it, I'm an honest guy), that I hadn't ordered a new A/C unit, so they reinstalled it. I don't think it ever worked right after that.

 
  #4  
Old 06-28-24, 01:02 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,968
Received 4,149 Upvotes on 3,726 Posts
There is a valve on the small line just inside the air handler.
It's either a metering valve or TXV valve.
Probably a metering valve. If they broke the system open and crap got in the line.... from brazing.... there could be something blocking that valve. I believe that would cause that line to get very hot.

The large insulated line should be very cold.... is it ?
 
  #5  
Old 06-28-24, 01:19 PM
F
Member
Thread Starter
Join Date: Aug 2005
Location: USA
Posts: 377
Received 0 Upvotes on 0 Posts
You kind of lost me on some of that terminology, Pete. I'll see if I can figure out what to check, and let you know what I find. Thanks!
 
  #6  
Old 06-28-24, 01:23 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,968
Received 4,149 Upvotes on 3,726 Posts
You can see the small copper line going into the air handler.
Just inside the cabinet is a metering valve. You can't see it.
It controls the flow of refrigerant into the evaporator coil.
 
  #7  
Old 07-05-24, 02:35 PM
F
Member
Thread Starter
Join Date: Aug 2005
Location: USA
Posts: 377
Received 0 Upvotes on 0 Posts
I checked the insulated line, and it is cold, but I wouldn't say "ice cold." The filter/drier starts out super hot, but after a little while, it cools down. When that happens, the unit stops throwing cold air. I can't tell if it needs to be charged, or if something else is wrong.

Hope you had a good 4th!
 
  #8  
Old 07-13-24, 09:57 AM
F
Member
Thread Starter
Join Date: Aug 2005
Location: USA
Posts: 377
Received 0 Upvotes on 0 Posts
AC starts cool, then goes warmer in minutes

Bryant 561C condenser, about 20 years old (but was accidentally removed/replaced by inept contractor when furnace was replaced about 14 years ago). I added a hard start capacitor several years back. System is kept clean. A-coil was replaced with the furnace. Just replaced the condensate pump. (Probably could have just replaced the bad valve in it, but wanted avoid future trouble, since it was old.)

When it starts, the air is cool (usually in 70's), but definitely not as cold as it should be (probably low on freon), and the filter drier is very hot. Line on both sides of filter drier is same temp, so that seems ok. After the unit runs for maybe ten minutes, the filter drier gets cooler, and the air gets warmer. Any ideas on how to troubleshoot this mess? I'm out of ideas, and can't find any answers doing online searches. Would it be worth having a tech run some leak sealer into the system, maybe?
 
  #9  
Old 07-13-24, 11:13 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 28,352
Received 2,319 Upvotes on 2,064 Posts
It may be icing up. It's a common problem when low on refrigerant.
 
  #10  
Old 07-13-24, 12:46 PM
F
Member
Thread Starter
Join Date: Aug 2005
Location: USA
Posts: 377
Received 0 Upvotes on 0 Posts
Thanks, Pilot Dane. I was wondering if that might be the issue. It was a bear getting the darned door off the coil - they wedged it in too tight, and caulked the bottom in place! I had to force it out using a screwdriver like a pry bar between the door and the top of the cabinet. Found a bunch of debris in there and got that out. There's a bunch of rust at the bottom right - I'm guessing that can't be good. Ran the unit with the door off, and the temp inside the coil ranged from 55 to 68 (with infrared thermometer). If it's that cold, could it still be low on freon? I didn't see any signs of ice in there, and the fins on the coil looked clean. Weird, it's 55 degree air in the coil, but the air coming out of the registers is in the 70's. Duct work is insulated, but apparently it's still losing a lot of chill along the way - even from a register that's only 10 feet or so from the furnace.


Rust at bottom corner of evap coil
 
  #11  
Old 07-13-24, 04:48 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,968
Received 4,149 Upvotes on 3,726 Posts
I combined the threads.

Awful lot of rusting for a new coil.

Have you gotten a new tech ?
You need to have the system pressures checked.
I previously told you what I thought the problem is.
It's not something that can be repaired by guessing.
 
flukeslapper voted this post useful.
  #12  
Old 07-13-24, 07:11 PM
F
Member
Thread Starter
Join Date: Aug 2005
Location: USA
Posts: 377
Received 0 Upvotes on 0 Posts
Pete, I haven't gotten a tech out here yet. The coil is around 14 years old now, I think. They replaced it when they installed the new furnace. I still don't like that rust in there, but I have no frame of reference for what a 14 year old unit should look like.

I appreciate your input, and was just hoping that maybe there was some type of diagnostic troubleshooting I could do myself, to figure out the problem, before having a pro come to repair it. I don't have an A/C guy I trust to be honest with me, so I thought having an idea what was wrong might save me a ton of money that I don't have. I'll see if I can find any recommendations from friends. The contractor that installed my system was highly rated, but when I called them, the owner had just let his son take over, and the son turned out to be a complete crook. I got shafted good, and don't want to experience that again. Have a great weekend.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: