instead of later?
Last fall, before it got cold I had my heater checked, and was informed that I needed- not 'might want', not 'might want to upgrade'- NEEDED a new furnace. Much better then than in the middle of winter, with a case of carbon monoxide poisoning.
Yesterday I called the folks who replaced the furnace to check the a/c. Before it got hot. And they discovered that the valves to the compressor had leaked all the coolant, and needed to be replaced. While they were at it, they asked if I wanted the coils in the outside unit cleaned? Having now seen the damn things, which were packed with old dust, dirt, and God knows what else, I said yes. What was interesting about that part was that they use a special acid. With the fan, etc., out of the way, they just poured the stuff all over the coils so it would flow down through them. It both dissolves a lot of crap, and as it reacts with stuff it foams up and the foam forces more out, and after a few minutes flush it out thoroughly with water, and the things gleamed. With, surprise surprise, much better air flow than before.
Happily, the same home warranty insurance that covered most of the cost of the furnace(and that I almost didn't renew) covered most of the cost of this. So, when it gets hot, I'll be able to cool things down.
God, I'm glad I found this now, instead of sometime in July.