How to Buy and Install an Insulation Blanket for a Water Heater

Insulation blanket for water heatersInsulation blanket for water heaters

An insulation blanket or insulation jacket is used on water tank heaters to reduce the standby heat loss or energy wasted during the heating process.

Buying and installing a water heater insulation blanket makes sense if you have an older electric unit, because new models come with the higher efficiency.

It is easy to test if your water heater is losing heat and wasting energy. Simple touch the outer surface. If it feels warm, your tank needs additional insulation. We suggest buying an insulation blanket with a higher "R" value (at least R-8).

Some manufacturers like AO Smith or Bradford White are designing water heaters to meet or exceeds National Appliance Energy Conservation Act standards concerning the insulation and standby loss requirements. The insulation is thick enough, so the standby heat loss is minimal and additional insulation unnecessary.

These water heaters are equipped with 2" thick foam and R 8.33 or higher insulation value, significantly reducing the energy waste and heat loss.

Every manufacturer explains rules in their manuals when covering a water heater with the insulation jacket, so warranty in some cases can be voided if you don't follow the instructions.

Why installing an insulation blanket is recommended

Here are the general instructions that cover important points of the unit and which can be affected by improper water heater blanket installation, lack of access, restriction of the air flow, heater malfunction, or even a fire:

  • Draft hood (gas units)
  • Thermostat
  • Controls
  • TPR valve
  • Water heater access door
  • Shut off devices
  • Don't cover safety tags with warnings and operating instructions

In the long run, insulation blankets are a good investment, especially these days with the rising energy costs. You can reduce the energy consumption by up to 10 % and make your unit greener with CO2 reduction as well.

You can buy a water heater blanket at Home Depot, Lowe's, and any other well-equipped hardware store, or online like Amazon. For less than 20 bucks, you can buy a jacket with the size that easily covers a 60-gallon tank water heater, two-inch-thick, made of fiberglass with R-6.7 insulating value, and with the included adhesive tape for easy installation.

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Installing an insulation blanket – Step-by-step guide

The insulation blanket installation is a DIY home project, and it doesn't require any special skills or tools. We suggest insulating hot water pipes also so together they can work more efficient.

Working on the electric units is easier than gas- or oil-fired appliances. Be careful not to obstruct the flue at the top and the burner area. Failure to do so could be very costly for you and dangerous.

Unless you buy a pre-cut hot water heater blanket, you just need adhesive tape and scissors to cut out the areas so you can clear the elements, as mentioned earlier.

Clean up the dust and wash the top surface so the tape can adhere.

  • Measure a water heater.
  • Use the scissors or utility knife to cut the insulation blanket to the water heater size, but be sure to make it a little bit longer (the length of the insulation strip should be the same length as the circumference of the heater plus 3" for example).
  • Wrap the insulation horizontally and around the unit.
  • Always try first to see if the water heater blanket fits correctly.
  • Use duct tape to seal the seams where they meet.
  • Once wrapped and taped, find where the controls and valves are and make the cut-outs.
  • If you need access to the thermostat, cut a three-sided flap so the top edge is still attached, so you can always tuck it back.
  • For the elements such as the drain valve or TPR valve, make the cut-outs to expose the parts.
  • Cut a cap of the insulation blanket to fit the top of the electric units, but never install it on the gas appliances.
  • Tape the remaining joints and seams.

Note: With the additional water heater insulation, do not set the thermostat over 130 F as the wiring may overheat.

Installing rigid insulation under the tank can also save you some energy and money. Think about it when installing a new heating unit.

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