Waco Home Inspection Part 7

Today's topic is going to be a brief overview of the safety components of a water heater and some of the latest trends in water heaters. 

Let's start with gas heaters. These have special considerations because they do burn gas, and therefore, have the potential to produce carbon monoxide among other things. Ideally, a gas heater will draw combustion air from an outside source, such as the attic or crawl space, or another exterior source. There are requirements for combustion air that should be met in general, and are related to the BTU's of the unit. Manufacturer's recommendations should be followed, and will vary based on the manufacturer, size and output of the water heater. When outside combustion air is provided, the water heater should be sealed from the living quarters, typically with a solid door and threshold. If outside combustion air is not provided, the room where air is drawn from should be large enough to provide the air, and a carbon monoxide detector should be provided! People lose their lives every year because they were poisoned by carbon monoxide, when a detector would likely have saved their lives.

If a water heater is located in a garage, it should be on a platform at 18 inches minimum. This is to prevent gas fumes from igniting and causing a fire or explosion. Some will say that water heaters now have FVIR, or flame vapor ignition resistant systems, and this is true, but I prefer to err on the side of caution and will recommend a platform if I happen to be inspecting your house and your water heater is in the garage. It should also be protected from possible damage by cars, either by location or with physical barriers.

Naturally, the gas connections should be proper and not leaking. If a leak is detected it should be addressed immediately.

Finally, gas heaters should have proper exhaust ventilation, which includes a type B vent that exhausts straight up, preferably. Again, you can not go wrong when following specific manufacturer's recommendations.

One safety feature that is present on all standard water heaters, and perhaps the most important feature, is the TPR valve, or Temperature/Pressure Release. If anyone has seen the Mythbusters episode on what happens when a water heater malfunctions either with temperature or pressure, then it has been firmly established there is a great potential for danger. Here is a link to that episode on you tube for your viewing entertainment: https://www.youtube.com/watch?v=9bU-I2ZiML0

Of course, all standard water heaters have TPR valves, so we are all safe, right? Not quite. TPR valves can become frozen shut or stuck. The best way to insure that the valve is working correctly is to operate it at least once a year. This really should be done by a licensed plumber, since these valves may develop a leak when "exercised" or there may be some other reason for it to be replaced. And yes, it really should be operated at least annually. Keep in mind that it is a safety feature. One other thing to be aware of with TPR valves is that they should be extended to within 6 inches of the floor with a suitable material for the heat and pressure, and should be the same size as the valve, typically 3/4 inches; the extension should never be capped, and it should not have threads that will allow capping! Sometimes PEX is used for an extension. While it is a suitable material, it is also flexible, and should be secured in such a way that it will not move under pressure.

With electric water heaters, the power supply should be armored cable or a similar suitable material, and the equipment should be properly grounded. In addition, there should be a means of emergency disconnect within 25 feet of the heater. 

While there are other considerations that go with inspecting a water heater, the items listed above cover safety in general.

In closing, there are two developments with water heaters that are relatively new. First, as of June 2015, water heaters are now required to meet an enhanced energy efficiency requirement, which requires more insulation. More insulation means larger heaters, increasing the diameter by about 4 inches. I am thinking of all those closeted water heaters out there that already have a minimum of space, and most of them are designed that way. Just a little thing to be aware of when you have to replace your heater. Another development that is gaining increasing popularity is the use of in-line or tank-less water heaters. These are available in both gas and electric models, are very space efficient, and are also more energy efficient. The early versions of these tended to produce less hot water than most people are accustomed to. However, more recent designs have improved substantially, and tank-less water heaters are becoming a more viable alternative. Again, the specific manufacturer's instructions should be carefully followed. So, there it is, a brief overview of safety items I look for when inspecting water heaters. Until next time, have a nice, and safe day! 


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