[QUOTE=hoopstar;34279]
Code:
        if temp >= 80 then gosub fan1on         ' fan ON at 80 
        If temp <> 70 then gosub fan1off        ' fan OFF at 70
Look at your original code...it doesn't make any sense.
If the temp is above 80, the fan kicks on...BUT...
if the temp is anything EXCEPT 70, the fan kicks off...

Change it to:
if temp => 80 then gosub fan1on
if temp <= 70 then gosub fan1off

Which is basically what you had in the first place. But I think you are sampling far too often. And I'd also throw a counter in there somewhere...something like if the temp is below 70 and you've checked XX number of times, then turn the fan off. (same thing with fan on). That way it'll keep from clicking on and off too often when the temp is right at the switch point.