I am going to assume the pad is concrete when mentioning cracks and breaks. If a composite or fiberglass pad, the same process and problems arise except, you can expect the pad to bend or crack more than to break. There's not a whole lot to worry about as long as you are careful and don't force anything. You want to be careful if raising the pad with the weight of the units sitting on it. You might end up breaking the pad in two. If you can raise the units onto some 2x4's bridging above the pad, you can do a better job of leveling the pad. Just be careful not to kink the tubing or put too much outward pressure on it. For just a few inches lift, you should be ok but just keep an eye on it. Try to make sure you get the pad as level as possible and as much dirt or sand underneath, as possible. Hollow areas increase the noise level and vibration might eventually break the pad. The compressor motors are mounted on springs and will compensate for an uneven pad. You don't want the pad to be over 3 degrees off level. Any more than that and you increase noise level and accelerated wear on the compressors (especially if they are reciprocating compressors). Depending on how well you can compress your fill, you might have to do this one or two more times over the next few years until the fill has fully compacted.

Thanks to Dovetonsils for the lead on the contactor (in my non-HVAC-speak, this would be called a relay). After a little web-searching Friday based on his\hersuggestion, I was able to pinpoint the contactor as the likely source of the problem and yesterday I put another one in. All is peachy now! For others with the same problem, I pulled the thermostat unit off the wall mount pins but the condensing unit continued to run, so I knew it had to be something with the circuit board on the air handler or the condensing unit itself. I then turned off the power to the air handler\circuit board, but the unit continued to run. At that point, it almost certainly had to be an internal wiring issue with the condensing unit. After making sure the circuit breakers were turned off to both the air handler and the condensing unit, I pulled the quick disconnect (what I call the wall-mounted fuse cartridge). I then unscrewed the panel on the unit. I saw the two silver capacitors that looked like whiskey flasks, and with a couple of insulated screwdrivers I shorted out the contacts on each. No sparks were noticed, but I had read that the wiring in the fan motor would have essentially discharged the capacitors soon after the power was turned off. Still, it never hurts to be careful, or put another way, it can sometimes hurt when you aren't careful. The contactor was obvious (I had seen a lot of pictures of it on the web by that point), and frankly a little disappointing in its simplicity. I took a bunch of photos of it with my phone from different angles, drew a diagram of it on paper indicating which wire went to what and how it was attached, and then labeled each of the wires with some tape ("upper left", lower right", etc.). Yes, this was overkill, but it was also new territory for me so I wanted to be sure to get everything back in the right order. I unscrewed the sheet metal screws holding the contactor to the internal sheet metal, then with it in my hand I pulled off or unscrewed the wires connected to it. I could now inspect the contactor, and could see that the contacts (like automotive distributor points) were both blackened and melted in places. The spring loaded plunger that raised and lowered the contacts seemed to be fine though (my assumption was that the plunger itself had some sort of problem, but that didn't seem to be the case). My guess was that the heat from arcing from the points to the copper plate might have caused the areas of contact to stick to each other. Whatever the problem, the contactor had to be replaced. I checked with all of my local hardware stores, appliance repair shops, and A\C distributors. Everyone was friendly and most had what I was looking for (a single pole contactor rated at 30 amps), but they all politely declined to sell me one, saying either that it wasn't an end user item ("not for the DIYer") or that they only sold to licensed contractors. I could see that these things are readily available on line and pretty standard in design. I was just about to order one when I happened to go out and get the mail. When I got to my mailbox I saw a truck owned by a friend of mine who has an apartment rental maintenance company. I explained what I was looking for and he said he had three on his truck. If I replaced it with a new one at some point, I could have one of his right now. Bingo. I hooked it up in a flash, remounted it on the sheet metal, closed up the panel to the condensing unit, and then began to turn the power back on to the air handler and the unit. I turned the thermostat to cool, and heard the lovely sound of both the fan and the condensing unit kicking in. When that side of my house got to the desired temp, the thermostat shut off, and miracles of miracles, the condensing unit did as well. Thanks to everyone else who provided advice. Unfortunately, I didn't see the answers until the morning, but all of the suggestions were sound one. Happy (and cool) Sunday to everyone! Nick in Palm Springs

It was indeed stolen. The property was bank owned and they had to get it to a habitable state to sell to regular homebuyers so installed a new one. The problem is the contractor installed a brand new air handler, thermostat and condenser onto an existing drain line and lineset. The AC apparently worked while being tested and was then left as a completed job. I bought the house and started the rehab. Straight away it kept cutting out or blowing warm air. It turns out the drain line was clogged which stopped condensation draining so a float switch kept cutting out (this took a couple of visits and a new float switchto figure out). But there also seems to have been a second problem with the line set, as whatever work is done (so far a new float switch, new second condenser, a new second compressor, a new evaporation coil...) it hasn't fixed the problem of the ac running and running and blowing warm air. My question is, am I expected to pay for a new lineset if he installs one as another attempt to fix this 4 month problem? So far it has all been under warranty.

When freon leaks first start to develop the leaks are often times slow. (It doesn't always work that way.) So what cost you money last year was a warning... some times this sort of thing can go on for years, sometimes not. The longer it goes, the leak gets worse and worse... the little leak becomes more and more. The amount required to get the unit to function varies. It depends on the unit, the line set length, the size of the line set, how much the outside unit holds etc. If the system is flat or nearly flat that is a significant leak. If you don't repair that leak now, it's only going to keep draining your wallet. The model you posted is the model of the indoor coil. It doesn't give us nearly enough info. But from what you did post... you have to fix the leak... that doesn't mean simply topping off the freon. System total freon charge can vary from a few pounds 'top off' as in slow leak --- 6-8 lbs to 20 lbs and sometime more. It varies. The larger the unit (capacity in tonnage), the more efficient it is, the more refrigerant there is, the more it will cost. I service the Katy, Texas area.