Why Remove Hot Water from your boiler
Did you know that the seasonal efficiency that oil boilers make hot water during the non-heating season is between 20% and 40%? If you have an old oil boiler with a tankless coil, you are on the low end of that extreme, and you’re WASTING between ½ and 1 gallon of oil per day every day your boiler runs just for heating hot water. This is because the same chimney that pulls hot flue gasses out of the boiler also pull warm air out of the boiler. A quick peek at that number is revealing; if you’re wasting 1 gallon per day, that costs you about $1200 a year in waste, not to mention that you’re still using a dirty expensive fuel to actually heat your water. Take a look at the attached article from the Brookhaven National Energy Lab if you want some third party analysis.
The good news is that there are solutions available for you. If you have a newer oil boiler, and you already have an indirect tank, a smart controller that purges the waste heat from the oil boiler into the indirect tank can cut your losses in half for a reasonable cost. If you don’t already have the indirect tank, or your oil boiler is older, consider a heat pump water heater which will heat your water using electricity at 2-3x the efficiency of a standard electric water heater. That’s the same as oil at $2 a gallon (and 100% efficiency). These magic boxes also dehumidify your basement. In some cases on demand propane water heaters make sense, but these are rare, as the price of propane is going up as fast as the price of oil.