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Hot Water Heater Insulation: Your Step-by-Step Guide

Just like insulating exposed plumbing pipes, walls, and roofs, when you insulate your hot water heater tank, you’re improving its efficiency and saving yourself money every month. If you have a new water heater, it’s probably already insulated, regardless of your sized gallon tank. But, if your tank is older, then you want to go take a look at it and see if it is insulated and, if so, if it has an R-value of 24 or higher. R-value is a way to measure insulation’s ability to resist heat or trap heat from traveling through it. The higher the R-value means, the better heat-trapping the insulation is.


If your water heater tank does not have an R-value of 24 or higher, your water tank is not sufficiently insulated. This means insulating the tank could reduce the standby heat losses by as much as 45 percent, and you could save up to 16 percent in heating costs, whether a gas water heater or an electric water heater. Insulation blankets are far easier to install than foam insulation or other extra insulation methods for hot water heaters. However, foil tape or other extra insulation for hot water pipes can also help.


Usually, once a homeowner insulates their water tank, they recoup their money within 12 months, even less if you have a large family that takes a lot of showers. Insulating your water heater doesn’t have to break the bank. It’s one of the easiest and most affordable ways to save energy and reduce your energy bills. For as little as $20, you can find water heater insulation blankets or pre-cut fiberglass jackets that are a cinch to install and improve the energy efficiency of your hot water tank and start realizing energy savings immediately.

Do you know the R-value of your water heater? If not, touch the tank. If it’s warm when you touch it, then it needs more installation, and since installing this additional insulation can be an extremely doable do-it-yourself home improvement project that many homeowners could undertake, looking into water tank insulation is worth it!


Before You Get Started

Before you start your DIY project, follow these steps:

  • Call your utility company and see if they offer rebates or if they provide water heater insulating blankets at a low price. Some utility companies will install them for you at little to no cost. Otherwise, they can be found on Amazon or other retailers by searching for water heater jackets, reflective insulation, insulation jackets, fiberglass insulation, or hot water heater blankets. 
  • Check your water heater and make sure it’s not leaking. If it’s leaking, you probably need to replace the unit.
  • Know what kind of water heater system you have, whether it’s a gas, electric, or tankless water heater. Because if you have a gas or tankless water heater, water tank insulation may not work as well for these systems.
  • If you have an electric model, you may want to add insulation (a bottom board) underneath the water heater as well. Adding a rigid piece of insulation or a bottom board under the unit can stop heat loss underneath the water heater, saving up to an additional 9 percent of water heating energy, according to the U.S. Department of Energy. However, installing the bottom board is best when a new unit is installed.

To install the blanket, you will need: 1) a helper, 2) scissors, 3) a marker, 4) a tape measure, 5) gloves, 6) a dust mask, 7) electrical tape and 8) a water heater insulating blanket kit.


How to Insulate a Hot Water Heater

Step 1: You will need to turn off the water heater.

Step 2: Measure the height of the hot water heater, and then cut the blanket so it will fit. Ensure you leave the top of the water heater open – you do not want to block the vent or the flue on the top of the tank for a gas water heater.

Step 3: Wrap the blanket around the unit and use the tape to hold it in place temporarily. We recommend positioning the blanket so the ends do not cover the access panels located at the side of the tank.

Step 4: Use the marker to mark the controls’ locations so you can cut them out. Also, leave plenty of room below where the valve and burner areas are located. When you make the opening, cut it at least 1″ wider than the area where the valve and burners are located. Be mindful of where specific parts are located on the tank. It’s essential to have proper room when cutting the insulation for items such as the gas valve, faucet, and especially any heating elements. You also want to mark where the pressure relief valve and pipe are located. If you’re not sure what this is, it’s the pipe that sticks out of the side of the unit.

Step 5: Line up the cutout areas carefully and then tape up the blanket so the installation is complete.Step 6: Turn your water heater back on. If you have an electric model, don’t let the thermostat get above 130° F with a jacket or blanket or it will be prone to overheating.


If installing Water Heater Insulation On Gas Water Heaters

It’s important to note not to apply any water heater insulation to the top of the tank for any gas water heaters. Properly inspect all venting areas on your water heater to ensure insulation is not blocking or obstructing any of these areas, allowing airflow into the burner area. Since gas water heaters have combustion air flow to the burner located at the bottom, not just the top of the tank, ensure the insulation does not come within 2” of the floor.


Water Heater Maintenance

Water heater insulation isn’t the only way to create an energy-efficient and cost-effective water heater for your home. If you properly maintain your system and proactively take care of any issues, your water heater can last you a long time.


Some common water heater items to watch out for include loss of hot water, low water pressure, coloring in the water, noises coming from your system, or your system has a visible leak. As a homeowner, you can combat some of these issues by performing a water heater flush once a year. This is to clean out any sediment or dirty water in your system and replace it with fresh water. Installing a new water heater dip tube in your system is another solution to some of the common problems listed above.


The best way to ensure a healthy water heater system is to have it serviced and inspected once every couple of years by a licensed professional plumber. These types of inspections include examining the system for any signs of rust, leaks, or other common water heater issues. A-1 Sewer & Septic Service plumbers are trained to complete inspections on all water heaters.


If you need a professional Kansas City plumber to assist you with a water heater issue, please contact A-1 Sewer & Septic Service Inc. to schedule a service call! When it comes to reducing your water heating costs, choosing the best water heater for your home, or a new water heater installation, it is almost always safer and recommended that you work with a professional plumber for the best long-lasting results.