We recently had a few 85 (and even 90) degree days here so I popped on the
A/C. It seemed to be running fine and cooling the house as usual. Then a
couple of days ago it got colder again, hovering in the mid 60s. At night, I
was pretty cold. I got up and noticed the thermometer on the thermostat was
about 10 degrees colder than the setting (not a digital) - but the A/C was
running.

It's been steady coming on and off as if it was cycling like it would be on
a hot day (let's say a day hot enough for it to come on every once in a
while instead of run constantly like when it's 95 outside). But there's no
real need for it to. So I bump up the thermostat to 85 or 90 or something to
get it to cut off and it doesn't - it's still coming on.

I turned the switch on the Tstat to Off (yes, the Fan is set to Auto, not
On) but it still runs! Yikes. I can turn it to heat and turn the heater to
50 degrees so it doesn't turn on and that seems to shut the thing down. -
Whoops, wait - Dammit - it just came on again - it seems that the blower fan
is coming on but the Heater's not on (it's still on 50).

Maybe the fan has just been running (cycling) but the A/C itself was only
turning on when it tripped - and just that fan air was enough to cool the
house down on those colder nights. But either way, if the fan is coming
n - OK, it' just turned off again - automatically when the thermostat is in
the Off position, something's obviously funky.

Should I flip the circuit breaker? Fortunately it's supposed to be 70s in
the days, and not below 50 at night the next for as far as my 10 day
forecast shows me.

Damn. It just came on again. The Tstat has been on Heat, Auto, and the lever
all the way back to 50 degrees this whole time (and the Thermometer reads
71-72 in the house).

Could it be the thermostat? I've been pondering getting a digital anyway.
Or is this something to get the HVAC guy in for? It really ****es me off
that our heater had to have a service call the first year we owned the house
and we've already had to buy a new AC 8 years in. Now here's another problem
with an AC that's 1-2 years old. I'm sure I'll need shingles on the roof
next.

Ok, it's off now and I flipped the switch to off. Let's see if it actually
stays off.

Any help on this is much appreciated,

Thanks,
Steve