Updated: November 2017
Water Heater Blanket Reviews:Are water heater insulation blankets really necessary? We hear that question asked a lot as homeowners are trying to be more conscientious about their energy use. The short answer is yes, but several factors go into "how useful" they really are. Many of the modern water heaters you buy don't require a water heater jacket since they are fairly well insulated to begin with. Other manufacturers strictly say NOT to use one. I, like many people, have my hot water tank out in the garage and so it stays somewhat warm, but certainly is not ideal. The one test that many experts tell you to do is to put your hand on the side of the water heater and feel how warm (or not) it is. If you feel any warmth, it means that heat is escaping and that the water heater could use a water heater blanket to keep the heat inside the tank where it needs to be. Many water heaters are designed to keep the water heated up to 140 degrees, so it's only natural to think that at those temperatures some heat would escape into a 60 degree garage.
Choosing a Water Heater Blanket/Jacket - Water heater blankets are sold through home improvement stores like Home Depot and Lowe's as well as in spots like Walmart or online at Amazon.com. The insulated sleeve that fits over the water heater is much like a "jacket" would be on a person. It keeps the warmth inside the jacket and doesn't allow it to escape. The heater blanket is usually made with sheet plastic that contains insulation on the inside. The water heater blankets are rated with an "R" value, much like other types of insulation you can buy. The experts we talked with said that an R-11 rating is what you are looking for. You will find water heater jackets for both 75 gallon and 80 gallon tanks as well as other sizes. They are really easy to install and cost roughly $15 to $30. In our online research, we found several energy efficiency websites say that a blanket for a water heater could save up to 35% of the energy bill that goes to heating and keeping your hot water warm in the tank. That's an extreme #, but many say 10-20% is more like it. That still sounds like a good deal to me. If the average family spends $20/month on the hot water heater, then saving $2-4/month can add up quickly and pay for the blanket within a year. When cutting the blanket to fit your water heater, make sure that on gas heaters you don't insulate the top or bottom portion. The flue draft and pilot light need lots of space. Thermwell is the most recognized name in this category and almost all hardware or home improvement stores will carry this brand. You can browse the best selling water heater blankets online here.