 There are also generous rebates on qualifying energy-efficient heating, cooling, and water heating equipment. So if you're a customer who receives a discount rate on your energy bill, all approved energy-efficient home improvements are 100% no cost to you. Even if you aren't, you can still get 75% or more off weatherization. Just dial pound 250 and say keyword assessment to see how you qualify and schedule your appointment. You'll also have the option to receive a one-time auto-dial text message from iHeartMedia. National Grid is a proud sponsor of MassSave.