I dont know all the details, but consider that some tankless hot water tanks also qualify for a rebate under the ecoENERGY grants

http://oee.nrcan.gc.ca/residential/p...lify-grant.cfm

plus these rebate prices should be for the federal rebate amount with certain provinces topping the rebate up (iirc ontario matches the federal rebate i.e. $250 + $250 = $500)

NOTE: in order to qualify for the ecoENERGY rebates you must follow the energy audit program.