A gas boiler and water heater only 80% AFUE efficient. Converted to Navien Combination gas boiler supplying heat and on demand endless hot water 95% efficient. Resulted in lowering utility bills.
An oil to gas conversion we did went from an 80% AFUE oil boiler to 95% AFUE high efficient gas boiler installing a Burnham Alpine that qualifies for a $2,700 rebate.
The installation of 2 Mitsubishi hyper heat units connected to eight indoor units. The homeowner went from a $1,500.00 a month propane bill to a $400 a month electric bill.