I have a return thermostat in the basement to get water temps after it's been through the hx and the dhw. It's the water temp on it's way back to the boiler. I imagine it looses another degree of 2 by the time it gets to the boiler. This thermostat reads 10 degrees cooler than the boiler thermostat. I keep the temps up pretty good until 8 pm. then I let the fire die till morning. I built another fire this morning but might hold off till the mixixng valve, or loading valve is installed. I also don't let anything call for heat until the return temp reads at least 140-150. Then I turn up the house thermostat 1 degree at a time cause the water temp drops so fast.