Zen and the Art of Water Heater Maintenance

April 16, 2008 11:14 AM

How do you maintain your water heater?

I live in a home with a water softener, and I'm not sure how often/what kind of maintenance I'm supposed to be doing with my water heater, if at all. I've not noticed anything detrimental in the quality of water in my house, but we have lived there for about 3 years and have never done anything with it.

It's located in the garage, and when I was cleaning out the garage last night, I noticed that there was what I'm assuming were some salt deposits on the outside of the tank - is this normal?

It's a gas water heater, if that makes a difference.

posted by po822000 to home & garden (7 answers total)

Funny this comes up, as we just replaced our ancient water heater. The plumber who did the work told us that in The Old Days, regular flushing of the tank was necessary to clear rust and sediment out. I'm not sure how many folks actually do it, though. It's what the spigot near the bottom of the tank is for, and there's a particular little bit of voodoo (open a hot water tap inside all the way, etc) involved to make sure you don't create a vacuum in the lines. Drain until the water runs clear, close the spigot, etc.

The new heater is apparently "self-cleaning", so no regular flushing is required. What this really means, an engineer friend of mine explained, is that there's a sacrificial anode within the tank that decays instead. It can be replaced, apparently. Otherwise I don't think there's much to it. Check the pilot occasionally. Look for signs of leaking - water or rust stains, etc. Our sort of crapped out slowly - it started as a tiny leak which seemed to stop on its own. We went ahead and replaced it anyway.
posted by jquinby at 11:26 AM on April 16, 2008

Some water heaters have a sacrificial anode, usually a magnesium or alimunim rod, that's supposed to be replaced periodically. It looks like a large hex nut at the top of the tank, you unscrew it (I don't know if the tank has to be off or not to do so) and you will find the hex nut is the top os long corroded metal rod. Go buy a new rod at the hardware store and screw it back in.

http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/96/960510.html
posted by StarForce5 at 11:45 AM on April 16, 2008

I'm not sure if I have a sacrificial anode - I think the water heater is from the early-to-mid 1990's; would heaters from this era typically have this sacrificial anode? If not, what about maintenance to older heaters?
posted by po822000 at 11:57 AM on April 16, 2008

The plumber that installed a new gas water heater in our house last week recommended annual flushing of the water heater, to help rid of the calcium build-up.
posted by jaimev at 11:59 AM on April 16, 2008

The sacrificial anode prevents rust. It has nothing to do with calcium build-up.

Flushing is still recommended as your energy efficiency declines dramatically the more calcium you have in the tank.

The anode, if replaced in a timely fashion, extends the life of the tank and prevents leaks up to and including ones that will completely drain the tank.

It is also possible to do what the majority of people actually do and just replace the whole she-bang when you notice a problem, but this is probably more expensive in the long run, even if you get more energy efficiency with a newer model.
posted by dhartung at 12:11 PM on April 16, 2008

The only warning is to remove power to the tank before you do any maintenance; you don't want the element to be on with no water in the tank or it will be ruined. Same thing goes for after any work, let the tank fill completely before turning it on again.
posted by shinynewnick at 12:45 PM on April 16, 2008

I think the water heater is from the early-to-mid 1990's; would heaters from this era typically have this sacrificial anode?

yes. Info on flushing and anode replacement.
posted by caddis at 1:29 PM on April 16, 2008 [1 favorite]