Lynn,
I wouldn't leave the chiller on at all. I'd remove it from the system and test it else where. Think of it like this.. you may have gotten LUCKY to catch it this time and may not a 2nd time. Let the temp come up naturally with the ambient room temp and seriously get some sleep. Without the chiller running it should be fine.
You do need a controller. With a controller you can control the heater and chiller in sequence to REALLY have steady water temps.
Good luck and GO to bed tonight
Hey HMA.... cool photo! Did you say for the next YEAR?
What's on your computer screen there
