water heater insulation

[herbd]

Hi,

I've been thinking of insulating the water heater (it is four years old) Question, how much difference does that really make?

Herbd

 

[glennjanie]

Welcome Herbd:
The blanket insulation is efficient enough to pay for itself in 1 year.
Glenn

 

[Michael Thomas]

This is a somewhat controversial topic in the Home Inspection industry, especially as some local energy codes may require a blanket. A few things to keep in mind:

1) Insulation blankets may void some manufacturer's warranties.

2) The listing of the appliance requires that the various labels be visible, people rarely bother to cut the blank to expose them. Again, this may void the warranty.

3) If not properly installed the blanket may interfere with air flow to the draft hood, if it slips down it may obstruct movement of combustion air to the burners, it may also interfere with the operation and inspection of control and safety devices.

4) According to the manufacturers anyway, modern water heaters are don’t need a blanket:

http://www.hotwater.com/bulletin/tcb1.htm

5) So a retro-fitted the blanket may actually decrease efficiency, see for example:

http://www.inspectorsjournal.com/forum/topic.asp?TOPIC_ID=3143

So if you do install a blanket, you want make sure it’s installed in compliance with the manufacturer's instructions, and inspect it regularly for slippage or damage.

 

[inspectorD]

Yup, Another inspector...oh boy you guys are gonna get a whole bunch of stuff now.

Just kidding...WELCOME Michael.

My two cents is ...skip the blanket, they are made good enough as they are now. A better use of your hard earned dinero would be to insulate the lines themselves for a couple of ten feet or so. This is where you will get more heat loss ...it's in the lines.

Then upgrade some weatherstripping on the house and doors and really save some $$$$

Good luck.

 

[mudmixer]

Any winter heat loss inside the building envelope is not really a total loss. The heat escapes one appliance to heat the air, which reduces the load on a main dedicated heating unit (the furnace). Not that much different than the heat from a refridgerator, freezer or even a cooking stove. - It just shifts the load and there might be a small loss of efficiency.

With a water heater, the biggest heat loss goes down the drain.

Summer is a diferent story.

 

[herbd]

Hi,

Thanks all for expert and thoughtful replies. I've insulated the pipes as far as I can reach, think I'll let the blanket go - the water heater does not feel warm to the touch.

Herbd