I have seen those blankets cause condensation to remain on the water heater,
thus rusting it out sooner than it should have.

wrote in message
ups.com...
the more insulation the better! Just DONT block venting or burner
access on the gas heater! or wiring access on the electric

if you can insulate hot water line between and leaving tanks, that will
save a little, and save running water till it gets hot too. insulated
lines are a save save save!!

They have premaid hot water tank insulating blankets. safe convenient
and pretty cheap.

just for the record I wouldnt leave any tank sit with stagnant water
hot or not for a extended time. if were on vacation for a week I make a
habit of running water espically hot but both when we get home, its
cheap and seems a good precaution...