I have three of the 1-1/2" plugs seen in the picture below on my buffer tanks. The heat loss probably isn't that huge, but I still think about it.
The jacket is something like vinyl over a 4" thick flexible foam. I haven't been able to think of a way to insulate them in a good looking fashion. Maybe someone out there has?
![[Hearth.com] How Can I Insulate These Plugs? [Hearth.com] How Can I Insulate These Plugs?](https://www.hearth.com/talk/data/attachments/151/151343-fd6d0f817cb07f050696335131dcaffd.jpg?hash=1HNA6KRcQQ)

![[Hearth.com] How Can I Insulate These Plugs? [Hearth.com] How Can I Insulate These Plugs?](https://www.hearth.com/talk/data/attachments/151/151343-fd6d0f817cb07f050696335131dcaffd.jpg?hash=1HNA6KRcQQ)