The only time that using an hour meter on EK or any other system might be nice is if the heating system supplies more than one rental unit and the renter is responsible for the heat. Actually, in that type of situation BTU meters are more accurate.

With the EK using an hour meter is not really going to give a good picture of fuel savings since it will vary through the year compared to a conventional system. The most accurate method is to track at least a year's consumption and correct it for the degree days of the time period. As the weather gets colder the fuel savings will decrease. In summer and shoulder seasons (apring and fall) when there's not a high heat demand, the savings will be much greater.