1 year old Goodman AC refrigerant leak

[Rtstrider]

Hello! I was greeted with the classic signs of low refrigerant on Friday. My AC was not cooling and the indoor coil was frozen as well as the compressor/copper tubes. Then everything thawed so I cranked it back on and grabbed the large pipe outside at the condenser...No temperature...Not even slightly cold...I went inside and grabbed the small pipe...Same deal. So they sent out a tech Saturday, they measured the pressures, and said he had to add a little over 4.5lbs of 410a to a 5lb system. The tech said they would do a leak test this week. So here comes the technician yesterday, he pulls out one of those sniffer tools, and says he thinks it's coming from the evap coil. He says they will order the coil and get back with me. I call up there this morning and his invoice said he didn't find any leak so they didn't order the coil. I guess my question is if the unit was installed almost exactly a year ago that 410a had to go somewhere right? Should I make any requests before the evap coil is replaced such as adding a leak detection dye?

p.s. Luckily this is covered under a 2 year labor/10 year parts warranty

 

[Al]

Frozen coils are not caused by low freon. It is usually because of lack of air low over the evaporator caused by dirty filter or a failure of motor winding on the fan causing it to run at too low of speed.

 

[Yah-Tah-Hey]

Low refrigerant level will definitely cause the evaporator coil to ice up.

 

[SrDriver]

+ 1 on the refrigerant leak. From what you mentioned sounds like that is the case. Pay a visit to the shop and tell them that the tech found a leak.

 

[Chris Meutsch]

I have a Goodman matched system. Evap coil went bad and leaked out, giving your symptoms.
My tech/installer replaced the evap for free because he said there was a major batch in from China that were bad.

 

[KzMitch]

Originally Posted By: Al
Frozen coils are not caused by low freon.


Originally Posted By: HosteenJorje
Low refrigerant level will definitely cause the evaporator coil to ice up.



Thanks.
Got it.

 

[Pop_Rivit]

Originally Posted By: Al
Frozen coils are not caused by low freon. It is usually because of lack of air low over the evaporator caused by dirty filter or a failure of motor winding on the fan causing it to run at too low of speed.


Interesting. I've always understood that if your air conditioner is low on freon, then your air conditioner can freeze up due to lower pressure inside the system. There is less freon in your system, but it is still being forced to expand the same amount – more expansion equals a cooler temperature. As your air conditioner’s evaporator coil drops below freezing, the moisture in your air will freeze as it comes into contact with your coil causing it to ice up.

10 seconds on Google and it would seem that most HVAC professionals would also disagree with you.

 

[Al]

Originally Posted By: Pop_Rivit


Interesting. I've always understood that if your air conditioner is low on freon, then your air conditioner can freeze up due to lower pressure inside the system. There is less freon in your system, but it is still being forced to expand the same amount – more expansion equals a cooler temperature.

I will back peddle somewhat. If you have a very light load, and/or poor flow...low freon "can" cause freezing. I would guess the OP has one of these.

But with a normal load and clean filter and proper fan speed (good flow). You will not normally have a coil freeze. The reason is that there is simply not enough freon for the whole coil to "freeze" keeping in mind that the incoming warm air across the evap coil won't allow that.

When the coil "unfreezes" and you turn on the unit you will see the side of the coil where the freon enters get frosty first.

I still would consider the low flow end of the equation even if it is completely freezing. It takes a while to freeze the whole coil with normal conditions (normal air flow and warm incoming air)

 

[Rtstrider]

Yep the filters were clean and the coil was very clean as well. I checked the drain and it was clear also. They measured the pressure at the schrader valves on the condenser. It's definitely a 410a leak somewhere.

 

[Cutehumor]

System one year old? Warranty? Let the tech figure it out. You said you have 2 yr labor/ 10 yes warranty on system.

Even though the evap froze, you could have a leak outside the home. I had a frozen pipe frozen outside all the way to the frozen evap in the attic.

 

[Rtstrider]

Oh wow! Yep I'm letting them figure it out! Just thought it was odd to happen right over a year!

 

[aquariuscsm]

Is Goodman a good unit? A house we may buy has a two year old Goodman AC.

 

[sleddriver]

Originally Posted By: Al
Frozen coils are not caused by low freon. It is usually because of lack of air low over the evaporator caused by dirty filter or a failure of motor winding on the fan causing it to run at too low of speed.

I disagree there Al. An Evap coil sure will freeze over if the charge is too low, and all else is working OK. Consult a P vs. T chart....

 

[Al]

Originally Posted By: sleddriver

I disagree there Al. An Evap coil sure will freeze over if the charge is too low, and all else is working OK. Consult a P vs. T chart.... [/quote]
I have done AC&R work and have seen it many times. Whatever..I'M done

 

[mk378]

Originally Posted By: Al
...you turn on the unit you will see the side of the coil where the freon enters get frosty first.

And this is the physics of how an otherwise normal system-- except for low charge-- can freeze up. The small cold spot ices over. Ice is a good thermal insulator, so the refrigerant and the cold spot moves further down the coil, and the next spot freezes. Eventually the whole coil is iced.

Meanwhile the house is still warm because the parts of the coil that are iced have no airflow, and those that aren't have no boiling refrigerant.

Of course inadequate airflow can also cause a freeze-up, so a proper diagnosis is important.

 

[FSully1]

Do you have paperwork where the tech wrote down how much refrigerant he added to the system?
If so, ask the service manager of the company why the tech added refrigerant if there was no leak.

 

[JHZR2]

Originally Posted By: mk378
Originally Posted By: Al
...you turn on the unit you will see the side of the coil where the freon enters get frosty first.

And this is the physics of how an otherwise normal system-- except for low charge-- can freeze up. The small cold spot ices over. Ice is a good thermal insulator, so the refrigerant and the cold spot moves further down the coil, and the next spot freezes. Eventually the whole coil is iced.

Meanwhile the house is still warm because the parts of the coil that are iced have no airflow, and those that aren't have no boiling refrigerant.

Of course inadequate airflow can also cause a freeze-up, so a proper diagnosis is important.


I agree with that. What people don't consider when saying low refrigerant is that there is a mass issue there too. Molecules are doing the work, and less pressure means less molecules to undergo the cycle. Problem is that unless it's cooling poorly, which can mean high air temperatures that keep the ice somewhat at bay, people often don't open the system and observe until it is too late...

To the op, I have to wonder if they're giving you the runaround to avoid a warranty service which may cost them. If the tech said there was a leak, I'd go there to the office if convenient, and ask to see the paperwork and the tech's notes.

 

[Rtstrider]

That's the oddity. The tech told me he added over 4.5lbs of 410a, then another tech came out Monday to do a leak check. His notes said he didn't find a leak. He told me he detected a leak at the evap coil. When his own company called him they said that he didn't find a leak but would be replacing the evap coil. Obviously there is a leak somewhere as this is a closed loop system. We have an appointment scheduled Monday morning for the evap coil swap out. Maybe we'll find out something more then. Just think it's kind of odd to be leaking like this right at 1 year.