I've had one HVAC tech come out and tell me that everything was in working order. But at nights when the temp reaches down to the level when the heat should be turning on, we can hear the pilot light turn on and off a few times before, I guess, a safety mechanism turns it off until it does it again. Eventually I turn off the system and in the morning I haven't had a problem turning back on the heat. What's going on? Any suggestions, thank you.

Help me understand... are you saying that only at night this happens? Does it happen during the day when the temperature is cold or no? It sounds to me like a thermocouple or sensor problem which is shutting down the pilot... but that would be anytime the heat is needed, not just at night... am I missing something?