1. Insulation selection

• Minimum R-Value of R-10. 

• Has a flame spread of 25/450 or less when tested in accordance with ASTM E84 or UL 723. 

• Clearly labeled with R-Value

2. Cut and fit insulation 

• Cut and fit blanket to allow for maximum continuous insulation of tank. 

• Fold the top 4" of the insulation blanket down so top edge will be finished with vinyl facing. 

• Leave insulation exposed at bottom to allow insulation to dry. 

3. Electric DWH: insulate top 

• For ELECTRIC water heaters ensure you cover top of tank with insulation. 

• For gas water heaters DO NOT cover top of tank, this can obstruct the draft diverter. 

4. Maintain clearance from gas valve and combustion chamber 

• Maintain a minimum of 2 inches away from gas valve and burner access panel. DO NOT install insulation below burner access panel.  

• Maintain a minimum clearance of 6" between combustible tank insulation and fuel-fired water heater draft hood and/or single wall metal vent materials

• Do not wrap the top of fuel-fired water heaters or cover combustion air intakes

5. Do not cover PTV 

• Do NOT cover the pressure temperature relief valve or discharge line with insulation.

•  IF relief valve exist but no discharge line. Install discharge line outside the insulation within 6 inches of the floor 

6. Electric DWH: Cut access panels 

• For ELECTRIC water heaters mark insulation to locate thermostat and heating element access panel. 

• Cut bottom and sides but NOT the top. This will create a hinge that allows access to these panels 

• Use tape to create a finished edge leaving no exposed insulation.

7. Secure with ties 

• Install nylon straps (like zip-ties) over the insulation within 6 inches of the top and bottom and one in the middle of the tank with minimal compression.

8. Clearance Requirements 

• It shall be considered feasible to install a Water Heater blanket whenever there is 2" of clearance around the majority of the water heater and at least 1" of clearance between the water heater and any obstructions. 

• Whenever there is an obstruction with less than 1" of clearance  and it is feasible to move the water heater to create the needed clearance without causing plumbing leaks or venting issues, the water heater should be moved.

  • Installer must verify any movement of water heater did not cause any plumbing leakage or have any negative impact on the vent.