140K Btu per gallon #2 fuel oil X 1100 gallons
154,000,000 Btu

8200 Btu per pound wood pellets X 8000 lbs

65,600,000

Assuming similar efficiencies for both heaters, you have less than half of the pellets you need. ( unless you burn half of your oil in the water heater.)

That seems pretty high from what other people are saying. I'm sure heating hot water doesn't take that much. maybe the 1,100 gallons is high its what my oil company said. I think space heating will use less than a central boiler. Will find out soon enough. thanks for your response

You can expect to use 1 to 2 bags a day.
2 x how many cold days you have in your area, = bags you need, divided by 50 bags = tons you need.

thanks for the info

we use just about 3 tons a winter , we live in seattle so not to cold.. but it runs most of the winter.

I used 5 1/2 tons the last two winters.