Monday, August 8, 2011

Helpful Household Hints: Water Heaters

It's been a while since you did one of these.

I know.  Real life intrudes.

Today I want to talk about water heaters.

What about them?  It's just a big tank full of hot water.  There's not much you can do with it, right?

Wrong.  There's a few things you can do to improve its performance and extend its life.

Okay.  You convinced me last time about how it's smart money to buy a few tools and do for myself.  So lay it on me.

First of all, your water heater uses either gas or electricity to heat the water.  If you have a gas water heater, be ready for it to die.  In my opinion, gas water heaters don't last as long as electrics.

Why is that?

Corrosive combustion products condensing inside the flue tend to attack the metal and cause it to wear out sooner.  That, on top of all the usual points failure in a water heater means a gas water heater generally goes toes-up at a somewhat younger age than an electric one.  But the difference is generally not noticeable, and the fuel savings of gas over electric is huge, so it's a wash in the long run.

Okay.  Let's say my water heater just died and I want to replace it.  What now?

First, turn off the water and turn off and disconnect the power or gas, and drain it.  Open a hot water faucet nearby, connect a hose to the drain valve at the bottom of the tank, and drain it by opening the valve.  If you have a window or doorway nearby you can just run the hose outdoors; if not you can take it to a nearby sink or toilet, but if the hose has to go uphill at any point, you'll probably find yourself carrying buckets of water.  Be ready for that.

If your water heater has a couple of shutoff valves in its water supply pipes, when you remove the supplies from the tank you can keep those valves shut, but keep the rest of the house's water on.  That means it isn't quite the emergency to get the job done quickly.

You still  want to get it done quickly, because you're going to want a shower at the end of the day, but at least your toilet and sinks will be working.

Once the tank is empty, you can remove any restraints it might have that keep it from toppling over (required by code in some places), and get it out of the house.  Most trash services won't take something that big, so you'll have to get it to the dump on your own or call a junk removal service.  But it's out of the house and that's the important bit.

Why does it say "fragile" on the box of the new water heater?  It's a big steel tank, looks pretty solid.

The tank is lined with glass.  That's slightly oversimplified but essentially correct.  Water attacks metal, but glass is effectively inert in the presence of water.  So the entire inside of the tank is lined with enamel or some other vitreous coating, just like a good cast iron bathtub.  Bounce it around or drop it, however, and the lining can crack.  That means water can get to the steel, eat it away and there you are after just a few months with a leaky tank, and doing this again.  So handle the entire tank as if it were all made of glass.

So you and a helper wrestle the new tank into place, reattach the water and power and/or gas, and there you are.  Let the water in gently.  Open that hot water faucet again to give the air inside the tank someplace to escape from.  Check for leaks as it fills, and as the tank finishes filling and takes on pressure, check for leaks again, looking everywhere you reconnected pipes.

All done?  Is that faucet done gurgling and spitting air?  Good, job's finished.  Turn the power back on, wait an hour and take a shower, you've earned it.

You said something about making it last longer, too.  I tried to save a few bucks by getting the shorter-warranty model, what can I do to keep it in good shape?

Like anything else, a water heater fares best if it gets a little maintenance once in a while.  Remember the drain valve on your old one?  Did you notice what kind of water came out at first while it was draining?  Pretty gritty, gunky looking stuff, I'll bet.

Every six months, hook up a hose to the water heater and drain off that sediment that's collected at the bottom of the tank.  Just let the water run until it comes out clear.  I've seen many pounds of grit and crud come out of the bottom of a water heater and the owner later told me it was as if I'd installed a new tank, twice as large as the old one.  But all I'd done was rinse out the sediment.  Results not typical, but you get the idea.  If space inside your water heater is taken up with something besides water, then obviously you're not getting the full benefit of the device.  Get that crud out of there and it'll be able to do more for you.

Check the thermostat setting.  I don't know what the factory setting is on your water heater but the last one I saw was defaulted at 140 degrees.  That's pretty hot, hot enough to do some damage.  If you don't need water that hot, turn it down to, say, 130.  I don't recommend much lower than that because you want to be sure it's hot enough to kill bad microorganisms like Legionnaire's disease.  130 will do it, 120 might not.

Double check the thermostat by running hot water over a candy thermometer.  Try to get it to within two degrees of the desired setting at the faucet.  If that means turning up the thermostat at the tank, so be it.

Insulate your hot water pipes everywhere you can.  If they're under the house in an unconditioned space, you give up an awful lot of heat to the winter air when it's cold out.  If they're running through the conditioned spaces inside your house, you're dumping a lot of heat inside your home, which your air conditioning then has to run extra to remove again, all summer long.  Either way, insulate your hot water pipes.  More insulation if you're already wrapped isn't a bad thing, either.

If it's electric and for some reason the heating elements go out, you can replace them.  Turn off water, turn off power, and drain like you're going to replace the whole thing, fit that big wrench onto the element in the side of the tank, wrench it out and wrench in the new one.  Apply a little plumber's grease to the threads or some teflon tape to make installing the new one easier.  Reconnect everything, check for leaks as it fills.

But mine's gas.

No sweat.  Check your burners from time to time.  Clean out the air intakes to be sure there's nothing interfering with proper airflow.  Check the flue, too - no leaves or bird nests (that's unlikely) clogging the output.  That could be deadly dangerous, the flue gases will kill you if they can't get out of the house.  Notice, I didn't say "might," I said "will."  Carbon monoxide is a primary component of flue gases and it has no odor or flavor, and you can't see it.  Worse still, it binds with hemoglobin preferentially, so the red blood cells in your blood tend to hook up with CO more readily than oxygen, and don't willingly give it up.  You can build up to a bad dose over a period of time, get to fresh air for a while, and come back into it and start back on building up a lethal dose, almost from where you left off.  It takes hours to flush CO from your system.

Anything else?

Just one more item, and this is difficult: if you can, replace the anode rod inside the tank every three years.  The anode rod is a sacrificial piece of metal inside the tank that corrodes before anything else does.  It's what keeps the tank from being attacked by water; as long as the anode rod is still there, your tank will probably last forever.  Replace the anode rod on a periodic basis, and you may never need to replace your water heater again.

This requires turning off the water and gas or electric again.  You probably won't need to remove the tank from its resting place.  You'll have to latch onto the rod on top of the tank, so you'll probably have to remove the water supplies so you can get the top of the tank jacket off, unless they've been convenient and made it possible to get to the rod without removing the top of the jacket.  Hook up a big wrench and about as big an extension handle to the wrench as you can find, and spin the rod off.  Lefty-loosy, remember.  Replace with a new one and enjoy a new lease on water heater life.

You may have to shop around for a new anode rod.  Lots of places don't carry them, since they simply accept that "water heaters wear out, there's nothing you can do."  Bosh and tish, says I.

When you go to install a new anode rod, give those pipe threads a gentle daub of plumber's grease.  A little goes a long way, and it also means that next time you go to do this, you might not need the extension handle.  It's worth the trouble.

Reconnect everything, check for leaks like before.  Job's done.  Sit back and relax and enjoy a new lease on water heater life, and the satisfaction of making a device that's expected to last only a few years, way more years than anyone ever expected.

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