How to get yourself into HOT water… forever

Question: Our home was built in the 60’s and my wife and I have lived here for about 15 years. We have replaced the water heater twice so far, once about two years after we moved in and again about 3 years ago. Should my heaters be wearing out this quickly and could I be doing anything to make them last longer?

Steve’s Reply: Have you taken a COLD shower lately? Probably not, if you live anywhere in the civilized world. Thanks to miracles of modern comfort called water heaters hot water, once only available to the privileged, is now taken for granted by almost everyone.

Last year about 10 million water heaters, were shipped new in the United States and about 8 million expired units end up in the land fill, unnecessarily. Water heaters don’t have to wear out.

Water heaters break because of one thing: lack of maintenance. Failure to properly maintain the heater results in rust, and rust kills it. The deaths are always untimely and like most indispensable appliances, water heaters often croak at the most inconvenient time. It’s not difficult to tell if your water heater has failed. The unheated bath water is a clue, as is the flooded garage.

Don’t feel too guilty about neglecting this wonderful appliance, it isn’t all your fault. Except for a (usually inadequate) drain valve, few residential water heaters are built with any thought towards maintenance at all. Manufacturers certainly haven’t gone to great lengths to tell you how to make their products last longer, for obvious reasons. Here’s what you can do to keep your water heater going indefinitely.

Let’s start with the easiest task, flushing out the sedimentary build-up. When water is heated, minerals are forced out of solution and form solids that settle to the bottom of the tank. This sediment is mostly calcium carbonate and the harder your water, the more of it your heater will produce. As this sediment accumulates on the bottom of the tank it can cause two main problems. First, the layer of sediment acts to insulate the bottom of the tank from the heat so that the flame must heat the tank hotter and hotter to warm the water. Overheating can destroy the glass liner and deform the bottom of the tank, predisposing it to rusting. Second, a dense sediment layer can act as barrier to the effects of the anode rod, leaving any exposed metal under the layer subject to the effects of unabated rust. Sediment is a sticky substance and cannot be adequately flushed if it is allowed to build up for too many years.

Flushing of the tank must be thorough and performed at least once a year without fail to have optimum effect. Unfortunately, the wimpy plastic flush valves provided by most manufacturers don’t provide enough flow to flush the tank rigorously enough. I recommend replacing the manufacturers valve with a _ inch brass ball cock valve (about $10) with garden hose threads so that you can attach a hose for frequent flushing. Lowering the water temperature to 135 degrees will also slow the build-up of sediment in the tank.

Most water heaters sold in the U.S. are steel tanks internally coated with a glass ceramic material similar to that on porcelain cooking pots. Whether fueled by natural gas or electricity, the water heater tank’s main protection from rusting is the glass coating. Unfortunately, it doesn’t completely coat the interior of the tank. Voids in the coating can and do occur at internal joints, welds, fittings, and seams. Cracks and chips in the liner can also result from rough handling during shipping and installation.

In order to combat premature rusting at these weak areas in the glass armor, manufacturers install one or two sacrificial anode rods in the tank. By means of an electrochemical reaction, the anode rod(s) (made of magnesium, aluminum or zinc) corrodes away instead of the steel tank. This reaction virtually prevents the interior of the tank from rusting--so long as the anode rod is in place. An anode rod under typical conditions will last about five years after which it must be replaced or the tank will begin to dissolve. The anode rod is located by finding a large hex shaped bolt head on the top of the tank. Sometimes the bolt is easily visible while other times the manufacturer has covered it over with insulation or a plastic cap or has completely hidden the thing under the sheet metal on the top of the water heater. The anode rod is so tightly bolted in place that once found, you will need a special tool called a torque multiplier (or, not recommended, a socket wrench with a 4 foot cheater pipe) to remove it. New anode rods cost about $15-25 and if you put a new one in every 5 years the tank should last many many years.

Another maintenance task you can do to extend the life of your water heater is to take a look at it now and then. A little attention goes a long way. Examine the water lines coming into the unit for signs of rust. Rust in this area is caused by electrolysis and can be cured by replacing the rusty parts with new plastic-lined steel nipples that have threads wrapped in Teflon tape.

Is all this worth it? If your current water heater is less than 7 or 8 years old, absolutely! After 8 years, the unit may still be worth the rehab if it hasn’t yet begun to rust and/or leak. A new water heater, installed, can run from $600 to $2000 depending on the size of the unit, access and the local building codes. You can make yours last indefinitely with just a little regular effort and few dollars in parts every five years. If you’re intimidated by replacing the anode rod, call a plumber. But beware, incredible as it may seem, most plumbers don’t know how to do this and will try to get you to buy a new water heater instead. Keep calling till you find a good one who knows what you are talking about. Contact wheaters@homepreservation.com for a list of sources for parts and tools for water heater maintenance.

Now go enjoy a nice hot bath. Ahhhhhh!

Steve Spratt is CEO of Home Preservation Services Inc. Click here to contact him.