Temperature drops too low before boiler fires again

There are periods of time where the system seems to work fine and maintains a nice temperature range between 73-74.

I have an intermittent issue where the room temperature drops too low before the boiler fires again. My thermostat is set to 74 and the radiators will turn cold. Eventually the boiler will fire up again, but sometimes the delay is significant (1 hour?). During this time, the room temperature definitely drops below 74.

Notes:

• I have a high limit aquastat set to 190
  
• My thermostat is set to 74 permanently
  
• Cycles/hour = 3
  
• My circulator pump runs only when the boiler is firing. When the boiler stops, the circulator pump also stops.
  

My understanding is that in most systems,

• Aquastat turns on the boiler
  
• Thermostat turns on the circulator
  

I don't think my system works this way.

• My thermostat seems to control the boiler
  
• The boiler controls the circulator
  

Since the circulator pump does not work during the boiler's off times, the stagnant boiler water is much hotter than the radiators. The aquastat measures this hot water as greater than 190 and therefore does not fire even when the thermostat calls for heat. Is this a crazy theory?