My Crown hot water boiler is about 9 years old and uses far too much propane than it should. Please help?

My boiler mate is using about 800 gallons of propane a year to heat water and the house. I have had it cleaned and serviced and still see no improvement in its usage. My home is about 1200 with new windows, siding and insulation. I recently purchased electric heaters to heat with, so I am only heating hot water for showers and such. There is only 3 of us in the house and the boiler mate is still using about 70 gallons a month just to heat hot water. Someone told me that we should be averaging about 15 gallons to heat the hot water. It is a Crown Gas fired hot water induced draft boiler with a bock boiler mate. I have hot water baseboard in the house. Please help the propane is outrageous. I am going to put an electric hot water tank in and heat with space heaters. Any information would be greatly appreciated. Thanks so much for reading this.