Ok - here we go. two years ago we had a 95% efficient 2 stage Frigidaire furnace installed. The following year we had a 16 seer high efficiency 2 stage central ac installed along with the air handler.

Today the central ac stopped and I checked the fuse box and nothing was triggered.

I called the guy who installed it and his phone is disconnected.

I had someone else who was referred to me come out today. He went right to the outside ac unit. He pulled off the side cover where the wiring is. He looked puzzled. He told me that the unit was not wired properly. He said the brown wire that runs from inside the house to the unit only has two wires inside. He showed me and it was a red and white wire under the brown wire sheath.

He told me that for a 2 stage system, it is 100% impossible to only have 2 wires connected to the outside unit, he says more were needed and should have been run in the first place. He said multiple wires were needed to make the 2 stage system work.

He then went into the basement and opened up the furnace (gas). He then said something else was wrong. He said all of the switches on the boards were not configured at all and must have been left in the position that the factory shipped it in. He said that they need to be adjusted (some up and some down) based upon the factory guidelines, and that my whole system has been running on 1 stage the whole time.

Is all of what I am being told correct?