I am planning to insulate my gas water heater (installed 1998). Other than not covering the top of the unit and the theromstat & other applicable parts, is there anything else I need to know before moving forward?

Follow the instructions that come with the kit. Do not block any combustion air openings.

Chrissy,

Are you insulating in an attempt to improve efficiency? There are a number of things that would improve efficiency before rapping the water heater. Has the water heater been drained (not completely) to allow sediment to be removed for the bottom? Has the burner or burner chamber ever been cleaned? Are the hot water supply plumbing insulated? These few items could have a bigger affect on efficiency then adding a wrap of insulation.

Is it natural gas or propane? Is it a direct vent with dilution blower? Are you on well water or city? You might do better replacing your current heater with a newer unit. It would be worth doing the calculation between gas and electric. With the prices of gas and the anticipation it will continue to rise, an electric water heater might end up being the better choice.

Regards,

Eric D