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View Full Version : Removing / Cleaning an A-Coil


bill022572
Jul 25, 2009, 06:02 PM
Hello all - first question in this forum. Have used plumbing forum and have always been appreciative of all the help. SO - I need to remove my A-Coil to clean it and have a couple of questions. I'm not really too cheap to pay someone to do this - but I like to do my own repairs. Oh - the unit is a 4-ton Payne unit with outside condensing and compressor unit and inside air handler ( evap under blower ). First - what I think I already know (please correct if wrong). 1. connect gauges to outside unit 2. close off valve on condensing unit to high pressure liquid line 3. watch pressure on suction side until reads
"0" psi and then close off valve on condensing unit at low pressure suction side and turn off compressor ( this traps all freon in condenser ) 5. un-solder liquid and suction lines inside house to air handler evap coil 6. take A-coil outside and clean. 7. re-install A-coil to air handler 8. re-solder lines to coil 8. open valves at condensing unit and let system re-pressurize for 10 - 15 minutes. My main questions are : what do I use to re-solder the lines when re-installing the coil ? Can I use silver solder with a propane or MAPP gas torch ? Exactly what is silver solder ? Another type of solder ? Would I have to use brazing rods ? Would this type of torch be hot enough to do this successfully ? Thanks for any and all advice / help / critiques - etc. I appreciate it. BILL

siberianair
Jul 25, 2009, 06:19 PM
I don't recommend using soft solder.. also need to vacuum system and get below 500 microns. Also need a license to handle refridgerant. Trust me you will need to add some. You will not be able to trap all refridgerant in system. Also refridgerant if ignited has same effect as mustard gas.
Honestly I would just clean it in p[lace. They sell eveap coil cleaners that are self disolving. If your coil is that bad brush it in place and than use cleaner. Save yourself the time headache and problems. This is a much bigger can of worms than you think. I am trained and rarly pull a coil to clean it. That is only for the worste of the worste.

bill022572
Jul 25, 2009, 06:59 PM
I appreciate the response. I was already pretty sure not to use soft solder. I didn't think silver solder was the same. As far as trapping the freon in the condenser - I actually had this repair done on my old unit quite a few years ago and the tech did not add any freon back when he finished - it worked fine after he cleaned the coil. This a fairly common repair down in South Florida.

wmproop
Jul 25, 2009, 07:43 PM
I would listen to the advice that Siberianair gave you,, but if you insist (GO 4 IT)
And pay the piper later

bill022572
Jul 25, 2009, 08:03 PM
Thanks for the response. So - you think it will be just as effective to clean it in place ? I know it will be quite messy - but would try this if it will work.

bill022572
Jul 25, 2009, 08:05 PM
Sorry - I forgot to add. Do you have any advice what type / brand of cleaner to use if I clean it in place ? Thanks again. BILL

wmproop
Jul 25, 2009, 08:13 PM
Hvac parts houses have several different kinds,brands, ask and they will help you
And it doesn`t have to be that messy,, take your time and keep the drain clear, let the dirty go down the drain

siberianair
Jul 26, 2009, 05:53 AM
Also might want to look into a new kind of filter. An evap coil cleaning regularly is a sign of bad filtration. It should not be that common of a repair.

bill022572
Jul 26, 2009, 07:51 AM
That's another reason I wanted to remove it myself - so I could remove the whole air handler and rebuild the air box it sits on. Whoever built it did a not so good job. Also I would like to build it a little higher - right now the only filter I can use is a 12" x 36" and it is not a readily available size. BILL

bill022572
Aug 4, 2009, 06:06 PM
Hello to all again. I really do appreciate all the advice. Another thought - I measured the temperature of the air coming out of my vents at various points and found the following. With my thermostat set to 77 degrees the temperature at my air intake was 77 degrees. When measuring at my nearest vent near the air handler - the temp was 57 degrees. As I moved further away from my air handler the temps went up and at my furthest vent - the temp was 65 degrees. My question : do these readings seem about right ? Thanks again for all the help. BILL

hvacservicetech_07
Aug 4, 2009, 07:36 PM
Your tempature drop is good, naturally you are going to lose a little once you get away from the airhandler.