Just aquired a used mach
Hi, this one will be difficult to trouble shoot with out being there, but there are some things you can check. You say there is voltage to the thermostat? This sounds like a power problem, or the unit is off on a safety. You have power going to both the unit on top and the indoor unit? I believe this is what you are saying. When this unit was removed, was any freon lost that you know of? If the unit on top was not pumped down which I believe on this kind of system, they are not set up with a pump down valve to pump the freon from the outdoor unit to the outdoor receiver unit so the top unit can be removed, the problem is its off on its low pressure switch because it has no freon in the system at all. The freon has to be recovered to remove the condenser from the roof, and when installed on your roof, it has to be evacuated with a pump and recharged. If it has pump down valves on the high side line, this valve has to be closed off while the unit is running, and the compressor will pump the freon into the condensers receiver. After it is connected to your indoor coil, it has to be evacuated and the freon has to be released by opening up the liquid line valve to let the freon go through the system. Both the indoor and outdoor lines ( freon lines ) have to be connected and the air has to be removed by a vac. pump to make sure all air and non-condensables are removed before the freon is let loose or it is charged to spec's. Don't worry about the run capacitor. I strongly believe this unit has not a drop of freon in it and I don't believe it has a pump down valve on the compressor, so the last owner either bled the freon into the air, or it has a valve on the compressor that you can look for on the smaller of the 2 copper lines. If there is, you should have the unit evacuated before you open this valve. If you want to open it and take a chance on it, turn the valve in like you are closing it, its the opposite of a water valve and the unit will start if there is freon in it. You may want to call this guy to see what he did and if he did pump it down to save the freon. It has to go somewhere when the unit is split apart. I hope the best for you, but this is the problem, it will not come on due to no freon or its in the receiver. Call him and find out what he did. Please let me know what you find out. Please rate me as I know you will be kind, and I will be here to help in any way I can. Keep me posted on this.
Sincerely,
Shastalaker7
A/C, Heating, & Refrigeration Contractor