Water heaters are a cornerstone of every residence, providing needed hot water for everything from food preparation to cleaning and bathing. Despite their critical role, too many people don’t understand how they work and all of the components that form this seemingly magical appliance. This comprehensive guide explores the components that make up modern water heaters, including both traditional tanked and tankless models.
Standard Tanked Water Heaters
The standard water heater has a storage tank that holds heated water until it’s demanded somewhere around your home. While many parts are similar between gas and electric models, this section will also explore all of the parts, both common and unique to each.
Cold Water Inlet
Every water heater has a cold water inlet, which is the supply pipe that feeds fresh water into the unit. There is often a shutoff valve at the inlet to allow for water heater servicing or turn off the water to the unit if there’s a problem.
Dip Tube
Most heating in tanked heaters happens at the bottom of the unit. This happens because cold water is denser than hot water, so it naturally sinks. The dip tube transports cold water from the inlet to the bottom of the tank. As it heats up, it rises toward the top of the tank and mixes with the rest of the water.
Temperature and Pressure Relief (T&P) Valve
Fluids expand as they heat up. In a closed container like a water heater, that causes the pressure inside the unit to increase. If that pressure gets high enough, it can split the seams of the unit, causing a catastrophic failure and both injury and property damage. The T&P valve is designed to release the pressure when it rises beyond the normal level to prevent damage to the unit.
Overflow Pipe
The overflow pipe connects to the T&P valve, allowing you to control the water that gets released in the event of unusual pressure. Be sure that you have this directed somewhere that’s temperature tolerant, such as your sump well or a utility sink. Check this pipe regularly to ensure there aren’t cracks or other leaks to prevent inadvertent damage to the area.
Drain Valve
Every tanked water heater needs a drain valve, allowing a service plumber to drain the contents. While this is important during a replacement, it’s also necessary to flush the system. Most manufacturers recommend flushing the water heater tank annually to prevent mineral deposits that can accelerate wear on the system.
Anode Rod
The anode rod, also called the sacrificial anode rod, is usually made of magnesium, zinc, aluminum or an alloy of these encased in steel wire. This rod attracts rust and other sediment from the source water to protect the water heater’s interior and slow corrosion. It’s recommended that you replace the rod every three to five years, depending on your water quality. Over the life of your unit, you may need to replace it three or four times.
Water Outlet
The water outlet is where the hot water flows from the tank into the network of pipes around your home. When you turn on hot water, the pressure in the water heater forces the hot water up through the water outlet while drawing in more water from the dip tube. If there’s an issue with the pressure in the tank, you may experience a lack of pressure from your hot water appliances.
Flue Baffle and Draft Hood
For gas-burning water heaters, the flue baffle is what the exhaust from the burner travels up through until it reaches the top of the unit and enters the vent pipe. At the top of the flue baffle is the draft hood, which connects the vent pipe to the unit.
Power Vent
Depending on where your water heater is installed, it may need assistance in getting the flue gases fully vented. These units use a power vent, which is a blower fan assembly that helps move the flue gases. This kind of assembly is especially important if there is horizontal venting for the unit rather than the standard vertical chimney.
Gas Burner Assembly
A gas-burning water heater will have a gas burner assembly that’s made of several components. This will include the burner, a gas valve and the pilot assembly. Then there are the safety mechanisms like the thermocouple that ensures the gas is burning and the flammable vapor sensor that checks not only for natural gas but also other gases like ammonia.
Heating Element
An electric water heater has an electric heating element as opposed to a gas burner. The normal residential water heater will have either one or two of these elements. These are typically located in the sidewall of the unit. If there are two elements, there’s usually one higher and one lower on the unit to allow for more even heating. These heating elements should last 10 to 15 years, which is about the same as the expected service life of the unit. They are normally covered by manufacturer warranties that can range from about six to 12 years, on average.
Tankless Water Heaters
A tankless water heater stores very little water but heats it immediately before it flows out of the unit, reducing the energy needed to keep stored water hot. Because of their unique approach to heating water, they have different parts than standard models.
Flow Sensor
When an appliance demands hot water, the flow sensor detects water flowing through the system and turns on the heating process. It’s this sensor that allows the system to heat water on demand rather than keeping water hot all the time.
Control Panel
At a basic level, the control panel sets the maximum temperature for a tankless water heater. The control panel may show error codes on some models if there are problems with the unit. On smart models, it’s the control panel that allows the unit to connect to Wi-Fi, transmit data about the water heater, and receive adjustments remotely.
Heat Exchanger
A heat exchanger allows the heat from the burned fuel to transfer to the water. In a tankless water heater, this is a series of copper tubes above the burner where the hot exhaust can flow over them. The water that’s being heated flows through the copper tubes where it heats up. How quickly the water flows through the heat exchanger will determine how hot it is when it flows out of the tankless water heater.
Since opening in 2007, Titanz Plumbing & Air Conditioning has provided a trusted plumbing and HVAC partner to property owners around Port Charlotte. Our team provides a wide range of residential plumbing services. These services include water heater, drain cleaning, repiping, backflow prevention and water filtration along with indoor air quality solutions and AC and heating installation, maintenance and repair. Call to schedule a water heater repair or replacement consultation with one of our trusted plumbers today.
