air handler coils froze up - question

   / air handler coils froze up - question #1  

Soundguy

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was out working in the yard today. wife called me in.. ac not cooling.

quick check.. drastically reduced air flow at the vents...controls set right, compressor running like normal.. no noises or ratteling.. cooling fan going.. inside garage, air handle sounds like fan is running fine.. pull filter.. WOW clogged.. we just started running the ac here in fl this month.. must have sucked up all the dust in the house.

Ok.. I'm no AC engineer.. but I know the physics.. plugged air filter reduced the air flow, and the coils were able to frost over, further reducing air flow.

I checked drain tube, it's open.. so.. at this point.. I turned off the ac and air handler breaker, and as far as I know.. I just let everything melt while I'm at work tonight.. then when i get home, make sure all the ice is gone and the water DID drain down the drain tube, and then button back up and go on my merry way with some cold ac tonight?

my missing anything?

thanks

soundguy
 
   / air handler coils froze up - question #2  
was out working in the yard today. wife called me in.. ac not cooling.

quick check.. drastically reduced air flow at the vents...controls set right, compressor running like normal.. no noises or ratteling.. cooling fan going.. inside garage, air handle sounds like fan is running fine.. pull filter.. WOW clogged.. we just started running the ac here in fl this month.. must have sucked up all the dust in the house.

Ok.. I'm no AC engineer.. but I know the physics.. plugged air filter reduced the air flow, and the coils were able to frost over, further reducing air flow.

I checked drain tube, it's open.. so.. at this point.. I turned off the ac and air handler breaker, and as far as I know.. I just let everything melt while I'm at work tonight.. then when i get home, make sure all the ice is gone and the water DID drain down the drain tube, and then button back up and go on my merry way with some cold ac tonight?

my missing anything?

thanks

soundguy
I think you are going to find that you are low on refridgerant or have a defective pressure switch.
 
   / air handler coils froze up - question #3  
Yep, that's usually a result of low refrigerant, so the next question is how low and why. However, if the filter stopped the air flow enough, maybe you'll be lucky and that's all. As for the condensation drain, some folks in the HVAC business say you should pour a little bit (maybe a cup of less) of household bleach in it a couple of times each season. I actually do it once a month myself.
 
   / air handler coils froze up - question
  • Thread Starter
#4  
comp sounded like it was running ok.. not kicking in and out. had a fan capacitor replaced outside late last year.. say september, refridgerant was ok then.. but I'll keep an eye on it.

if it ices up again I'll call the ac man out.

I'm hoping it was just the plugged filter.

And I do mean plugged! couldn't see light thru it. I must have forgot to change the ac filter at the end of last season before I started it up this year. ( we don't need to use the heat during the winter here in florida.. so it hardly ran since last year. )

crossing my fingers.

soundguy
 
   / air handler coils froze up - question #5  
Reduced air flow will definitely cause an ice up.

I bet you got it with your filter change.
 
   / air handler coils froze up - question #6  
Probably just the dirty filter. A dirty filter will frost off the A coils as you described. Low gas will as well but since you found a very dirty filter I would go with that. Watch it fro a few days if it low on gas it will do it again in a few days if not sooner.
 
   / air handler coils froze up - question
  • Thread Starter
#7  
when I get home tonight I'll put the coil cover and fan cover back on and turn her on.. I'll monitor the air flow to see if it tapers off again.. and if so I'll pull the cover to check for ice up.. if it does it again/.. I'll call the ac man.

thanks for the advice guys.

My fault on the filter... I shoulda remembered to change it at the end of last season...

soundguy
 
   / air handler coils froze up - question #8  
If you stop the compressor, but leave the fan running it will defrost much quicker. Of course some of that ice will evaporate into the room. Still it will defrost quickly.
 
   / air handler coils froze up - question
  • Thread Starter
#9  
i had to leave to go to work for 6hrs... so I left it open.. it's in the garage in florida.. I'm sure it will be defrosted when I get home tonight.

however, thanks for the tip. I'll remember that if it ever happens again ( hope not ).

again.. thanks to all.

soundguy
 
   / air handler coils froze up - question #10  
clogged / dirt filter will cause the coil to freeze up. Been there done that.
 

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