We had a new oil furnace put in in Dec just past, our central ac is 10 yrs old & was working just fine last summer. The co. who installed the furnace said they had to tie something? In with the ac unit, but being winter they would come back in the spring, no calls to do that & I didn't think about it, it got warm I turned the ac on & it blew warm air, shut it off. Called the ac co. out, they looked at the unit & told us it was bone dry, I told them what the other co. had said ,they went in & looked & said they didn't ,so there lies the reason we were empty. Thye come out & said, loss charge pumped down & charged leak,found leak at the suction service valve, had everything working ,that we were good to go, later in the day warm air again, shut the ac off, called them back, when they looked at it ,they said refrigerant was low & then said the compressor just stopped, & they left & left no paperwork, I'm in a real mess here