On our hot water heater someone wrapped it with insulation and I did not think anything about it. One day my plumber friend said I should take it off because it could cause condensation on the outside.

So what do you guys think? on or off?

What R value is that little big of insulation really providing. Might as well just leave it off.

Never seen a water heater with insulation wrapped around it.

Back in the '70s and '80s wrapping a WH was seen as an positive incremental effort in energy conservation. There are probably still companies, operating on government subsidies, who come into a home, install weatherstripping on doors and windows, wrap the WH, etc.

A modern WH is so well insulated no wrap is required. Even with me gone for two weeks and my WH gas valve set to pilot-only, I'll bet you I could take a shower with the water in the tank. If I remember, I'll get a digital reading Mon/Tues, two weeks after I shut it down.

Wrapping looks ugly, gets in the way of service, and usually appears of amateur installation.

quote:

Originally posted by Woodman:

Wrapping looks ugly, gets in the way of service, and usually appears of amateur installation.

Absolutely.

Back from the land of free grapefruit. Here's the follow-up on WH temperatures after I was absent for two weeks and the WH was set to 'pilot':

Outside temps dropped into the teens. It was 30˚ when I got home. The house was 50˚. The basement, 57˚, as was the cold water sitting in the water pipe (from the street, the cold water is about 48˚).

The water in the WH was a few tenths under 100˚. After sitting for 16 days. Plenty warm to shower. Although after 48 hours in the truck, I cranked up the WH while unpacking. It takes about 45 minutes to make virtually unlimited hot water. Enough (steam) to set off a smoke detector in the hall.