Ever wondered how to properly install a water heater? Worried about making some mistakes? Here are some common water heater mistakes, and some could even become life-threatening. For many people, installing a tank water heater may be easy, however, these are often the people who actually fail the inspection. Indeed, a water heater can be easy to install, but replacing one in an existing home can introduce a host of complications, including possible water heater code violations, number one being they don’t typically go seek out a building permit for a replacement water heater. Here are some common code violations and many professionals see out in the field when looking at water heaters, and replacement water heaters.
- Unsupported expansion tanks:
Some folks may tell you that an expansion tank is required at every water heater, but that isn’t in the IRC. Where requirements for expansion tanks show up in local codes, they’ve been added in. What is required is “a means for controlling increased pressure caused by thermal expansion … where required,” and that’s only necessary under certain conditions. Figuring out whether a particular installation meets those conditions can be difficult. The simple solution is to just add an expansion tank, but because it’s an easy way out, the standard position in many cities has become “expansion tanks are required.” However, the real answer about whether they’re required should come from a professional water heater installer. And there are other devices and methods for controlling pressure other than expansion tanks. When expansion tanks are included, physical support for them is a concern, as installers often leave them simply hanging by the pipes they connect to. Definitely read the manufacturer’s installation instructions before you do that. It’s not a good choice, and some local codes prohibit it.
2. Unlisted cord and plug:
Most items in this article only apply to conventional gas water heaters, but electric water heaters are also common. The hazards of combustion air, gas, and venting are eliminated with electric appliances, but there is still one common violation to be found. These appliances are generally intended to be hardwired to a switch location, but installers often buy a generic cord-and-plug assembly and plug them into an available outlet. Just to let you know, electric water heaters can only be installed with a cord and plug where listed by the manufacturer for such installation, and they must use a cord and plug that has been listed for use with the specific make and model of water heater. This rarely happens, which is why hardwired installations are recommended instead.
3. Confusion about pans and drains:
Drip pans are required when tank-type water heaters are installed in places where a leak could potentially cause damage. These pans are not meant to protect from a catastrophic tank failure, however they are meant to catch the slow leak that no one notices. In a basement with a concrete floor, damage is not generally a concern. But when the basement is finished, it may be. Drip pans in new homes also require drains. Neither pans nor pan drains have always been required, and they have been a tricky issue when it comes to replacement water heaters in newly finished spaces. The pans themselves must be installed if the water heater is located where a leak can cause damage. Prior to this, the top violation would have been not installing pans and drains with replacement water heaters—now, the issue is inspectors continuing to require drains without notice of this code change.
4. Improper TPRV pipe installation:
The temperature pressure relief valve (TPRV) is an incredibly important life-safety device on every water heater. Its proper installation is the difference between a nice hot shower and an explosion. Unlike the expansion tank, which is intended to protect the piping system from pressure, the TPRV protects the water heater tank from experiencing more pressure than it can actually handle. Here’s how your water heater becomes a pressure bomb: The boiling point of water that we are familiar with – 212°F – is the temperature at which water at sea-level atmospheric pressure turns to vapor and greatly expands. But as pressure increases, so does the boiling point. This means that when pressure builds up inside a water heater, liquid water can get hotter than its atmospheric boiling point, until the tank ruptures. When 40 or more gallons of superheated water is suddenly brought to atmospheric pressure and instantaneously vaporizes, the massive expansion can launch your water heater through your house. The TPRVs themselves are not usually a problem on water heater installations, as they come installed in the water heater. The problems occur in the pipe between the valve and the discharge point. The IRC provides a list of 14 specific criteria meant to keep this pipe open. Many installations are tripped up by a number of these specific requirements.
5. Not enough vent and vent-connector clearance:
Conventional tank water heaters generally utilize two types of vent and vent connectors: B-vent and single-wall. These vents get hot by design—a hot vent is part of what produces the draft required to remove the combustion products from the building. But B-vent and single-wall are not the same. B-vent has a pipe inside a pipe with an air space between them that insulates the outer pipe from the hot inner pipe. Because the outer wall of B-vent doesn’t get all that hot, code requires only 1 in. of clearance between it and combustibles. Single-wall vents get very hot, requiring a 6-in. clearance to combustibles. In an attempt to maximize finished floor space when boxing off the water heater from the rest of the room, people often don’t leave enough clearance between the new wall framing and the vent pipes. Basement remodeling and finishing projects are notorious for this code violation.