You should have posted this to the origional thread so those who try to help have benfit of what's been done to this point. But that's behind us now so let's see what's happened. I noticed you used acid cleaner(which I am familiar with but don't reccomend for your first time cleaning coils without a professional in attendance). Did you follow my instructions using water afterwards or just use the acid cleaner?

Yes, I did spray water to rid of the cleaner residue, then , followed by steam cleaner briefly.

Good,I feared the acid wasn't completly removed and had damaged the coils and/or electrical componets/.
There is no telling about what they wrote considering they didn't know how to fix it.
#1. Is the compressor PLUS both (indoor&outdoor) fans running?
#2. Are you "CERTAIN" the aux heat wasn't what warmed for 2 days? The aux kicks in to assist compressor even when switch isn't set to aux/emerg position.
#3. Does the circuit board have a light(s) that flashes codes?

It is starting to point toward a bad/loose conection as a possible problem.

Klem1, to answer your questions:

1. Yes, both fans are working properly
2. I was monitoring how it heated up. Since two degrees above set-temp would trigger the aux to kick in, I always added only two degrees or one higher than the room temp to slowly reach up the desire temp. I am pretty sure that only was the stage 1 used without aux or emerg.
3. No the circuit board does not have any light indication

Your mark reminds me that when I put the new board in hurriedly before getting dark, I missed connecting two places. I was so disappointed that the new board was not working. However, since I was in a hurry putting it in, I determined to make sure all connections were good the next day. If it is indeed a loose connection, then I'm all happy that I can unscrew the cover and check all the connections. Well...it's dark now. Work for tomorrow then :-)
* my husband did bang on the cover, because we couldn't line up the multiple panels to match the screw holes.... well...he gangs everything when it's not working........LOL

This post was edited by chueh on Fri, Jan 10, 14 at 19:04

Banging does little good unless accompanied by aproperate language. It sounds like you all are looking all the right places but may be nearing limits of what can be done without training,experiene and tools. Do you have a VOM and/or amp meter? Visual inspection often reveals a problem if one knows what they are looking for but the best pro around still relies on his meters. Anyhow,lay your hand on the compressor or test amps to see if it is running. If it is running but no cooling or heating is taking place,you have your work cut out without guages and meters. Here is somthing the two of you can team up on. After unit has been idle but with power available 5 or more hours and of course T-stat set as not calling for heat. Joe go's to outdoor unit and listens very close when he tells Moe" turn it on". What Joe is listening for is the sound of compressor coming on then quickly going off or struggling to start then going silent. That should hold you while I read more in the book mom bought me for my 17th birthday,All you ever wanted to know in life but were afraid to ask.

LOL blem1.... yep! Banging alone is not complete yet!!!

I could only check the PHYSICAL connections of all parts on the board, and then it rained. I would use the amp meter to check tomorrow if it's not raining. I would watch some youtube videos, but if you don't mind, can you briefly tell me what the essential parts and places I need to check and tips for that? Thanks

You need only see how many amps is being drawn through either 240volt supply to know if compressor is running. There is a tag attached near panel over electrical.
The tag tells you how many amps compressor draws ( compressor FLA ) and fan ( fan FLA ), If unit is only drawing fan FLA +/- 20%, the compressor is not running. If unit is drawing +/- 20% combined FLA for fan and comp, the compressor is running and heat or cool would be functioning enough to be felt in discharge air but not nessarly normal. Amp draw of more than 200% fran FLA but less than 50% combined FLA indicates possible low on freon,bad compressor,metering device malfunction or such. You are nearing the point of calling in a pro.

Well.... I guess I was delusional about both outdoor and indoor fans were running. They indeed, but I was not paying close attention to the fan outdoor when I first started noticing the air sent out was cold. When you asked me if the fans were running, I was having the impression of both fans working during the two good days.

The thermostat triggers the fan when trying to work, yet the outdoor unit did not do anything (no compressor-kick-in sound). No sound at all...

I checked to see what could be the solution online. I narrow down to tow possibilities, other than not getting power from the power company: bad transformer or contactor. They don't cost much, and I could probably replace a new one myself as the defrost control board I did. However, the problem is that the heat pump company is not longer existing. I was lucky enough to find a defrost board last year and this time, which two HVAC companies told me they could not find.

I guess moving the top panel which the fan attached to affecting the wires or cords of the fan or for some reason the compressor was damaged... well....gotta call the pro, as you suggested. BUT....it's hard to find a real pro though.....I seemed trying almost every HVAC companies locally....

Anyhow..Klem1..thank so much for your help. You've done everything you could to help me.

This post was edited by chueh on Sun, Jan 12, 14 at 11:46