The basement is appx. 20 feet wide and 27 feet long. The new gas service line has been installed just next to the front-right corner of the house.
The existing oil boiler is located in front of the chimney, which is about 4 feet in from the right side of the house, and about halfway back (about 13.5 feet from the front wall).
The existing oil tank is in the front-right corner of the basement, just on the other side of the wall from the new gas service line.
The house has about 1200 square feet of heated living space. There are two heating circuits, one for old radiators, and one for less-old baseboard units.
The second floor uses exclusively radiators. The one in the bathroom is 20" tall and 21" wide. The other three on this floor are all 38" tall. One is 24" wide, and the other two are 15" wide.
There are also two radiators on the first floor. They are both 38" tall and 24" wide.
All of these radiators are controlled together by a single 2-wire thermostat on the second floor.
The first floor has two non-radiator units. The front room has a baseboard system, which stretches a total of about 23 feet along the right-side and front-side walls. The kitchen has a single kickspace unit.
Both of these units are controlled together by a single 2-wire thermostat in the kitchen.
The existing oil burner is a Burnham V8 unit. Model number PV83WT-TLWF-1 , manufactured in 2001. See photos for specs.
This boiler has a built-in coil for domestic hot water. There is no separate water tank/heater.
Most of the heating system uses old, thick iron pipes to transfer water between the boiler and the radiators. However, the kitchen kickplate unit, and one of the upstairs radiators uses flexible plastic pipes
We also have heat pump units that we use for AC in the summer, and for heating when the outside temperature is not too cold.
There is a "logic" unit that knows how to disconnect the two 2-wire thermostats when the outside temperature is above freezing. That means the thermostats never call for heat, and therefore the oil boiler will not turn on. When the outside temperature falls below freezing, the thermostats get reconnected to the boiler.