After you give your water heater a good visual inspection, there are some other very important safety items you need to check. The first is the Seismic Strapping. These are metal belts that strap the water heater to a wall. The seismic strapping holds the water heater upright in the event of an earthquake. The straps are not intended to protect the plumbing, or avoid flooding. Instead they are specifically required to protect the gas lines. During an earthquake, the water heater can move substantially. Even if it does not tip, the somewhat fragile flexible gas line could easily be broken, which could leak gas and cause numerous fires.
When the requirement for strapping was first introduced, plumbers used what is known as “plumber’s tape” to secure the water heater. Plumber’s tape is that thin metal strapping that they use to support pipes under a house or in an attic. It is about 3/4 inch wide with holes running down the middle. But due to all the holes, the plumber’s tape easily breaks. Remember that a full water heater can weigh several hundred pounds. Plumber’s tape is no longer considered adequate for strapping a water heater (see picture at left). Instead you
should use a water heater strapping kit that is available at any home improvement store. These kits contain two metal bands with mounting hardware, and when properly installed will reduce the likelihood of your water heater jumping around during an earthquake.
The proper way to install the straps is to use two straps. One at the top 1/3 of the tank, and one at the bottom 1/3 of the tank. A general rule of thumps is to install the straps 9 inches from the top of the tank, and 4 inches above the contols at the bottom of the tank. The straps should be secured to a stud in the wall with a 3 inch lag bolt. Do not use plastic anchors in the drywall. The straps should be looped around the tank. And finally, if the water heater stands more than three inches away from a wall at the back, a supporting brace or block should be used.
If your water heater is in the garage, it should be placed on a platform that is 18 inches above the ground.
This too is a safety precaution against fires. Many of us store items in the garage that give off fumes. These could include gas for a lawn mower, paints and varnishes, and even some cleaning products. There could also be a leak from a gas line from a clothes dryer or even the water heater. Most of these fumes will sink to the ground in a similar way that oil and water separate. The vents in the exterior walls of your garage should allow the fumes to escape. If your water heater was sitting on the floor and enough fumes collected, a fire could easily start when the water heater ignites to heat the water. It happens all too often. If your water heater is in the garage and on the floor, you need to have it raised.
To determine the age of your water heater, you will need to check the serial number on the tank. Newer water heaters will print the date of manufacture, but older units used a date code included in the serial number. Some are easy to desipher; the year and month or year and week are the first four digits of the serial number. For example a tank manufactured in March of 1999 will have 9903 as the first four digits (or 0399 depending on the manufacturer). Other companies use a date code using letters. If you cannot determine the age of your water heater, call a plumber or a Home Inspector to help you determine the age of your water heater.
We recommend replacing older water heaters. Water heaters become less efficient as they age due to sediment that builds in the tank at the bottom. This sediment acts like an insulation layer which causes the water to heat slowly, and requires the burner to stay on longer using more gas. This can also cause over-heating of the surrounding area which is a fire hazard. The other reason to change an older tank is to avoid leaks. In a perfect world, water heaters would fail with only a little drip. Unfortunately water heaters can fail with catastrophic results. Since your plumbing system – and the water heater – are under pressure, failure can send excessive amounts of water pouring into your house. Even if your water heater is in the garage, the force of the water can quickly disolve the drywall, and end up in your house ruining flooring, drywall, and personal items.
And finally, don’t store items up against your water heater. It is particularly important not to store combustible items such as wood, cloth, cleaning supplies, etc. But even non-combustible items can reduce air flow and cause the water heater to over-heat.
For more information about home inspections in San Diego, please visit sdinspect.com