Support / / Glossary of Terms

Basic Water Heater Terminology

Limited Warranty – The Limited Warranty on the tank and parts is the number of years after installation that State will replace the water heater at no charge if the tank leaks, or replace component parts if they malfunction. Both tank and parts warranty applies if failure is due to manufacturing defect. Complete details on State water heater warranties are included with the water heater or are available from the State Customer Support. State offers the following basic warranty choices…

Rated Storage Volume – The measured storage volume defined by the Department of Energy. 

Input - The amount of gas or electricity used per hour to heat water in the tank. Higher input means the water heater can heat more water faster when needed. Natural or propane gas input is expressed in BTU’s (British Thermal Units) per hour, and State gas inputs range from 30,000 to 75,100 BTU’s. Electric input is expressed in Watts per hour, and State electric inputs range from 1440 watts to 5500 watts.

Recovery (at 90º Temperature Rise) – Converts BTU or Watt input into gallons heated per one hour (GPH). For example, a State 1212 Series 40,000 BTU gas water heater recovers, or heats, 41 gallons in one hour. 90º Rise indicates that incoming cold water is increased in temperature by 90ºF. State recoveries range from 31 to 81 GPH on gas models, and from 7.5 to 25 GPH on electric models.

First Hour Rating - This peak demand figure estimates how much hot water the water heater will deliver during the first hour after you start using hot water. First Hour Rating combines the heater’s Rated Storage Volume with its Recovery during one hour of operation. 

Energy-Efficiency Terminology

Uniform Energy Factor – The Uniform Energy Factor (UEF) is the measurement of a water heater’s overall energy-efficiency. A higher Uniform Energy Factor means a more efficient water heater and energy cost savings for the homeowner.

Insulation R Value – A measurement of how well a water heater’s insulation will help prevent radiant heat loss through the tank. The R Value of one inch (1”) of foam insulation is 8.33. A higher R Value will help increase the overall Uniform Energy Factor.

Heat Traps – Special fittings installed at the water heater’s cold water inlet and hot water outlet connections. Heat traps help prevent heat from escaping through these connections during standby periods and help increase the overall Uniform Energy Factor.

Self-Cleaning – A special feature on BETTER and BEST State water heaters, which introduces cold water into the tank in such a way that very small particles of lime and other sediment are kept in motion so they don’t accumulate on the bottom or the tank or on the electric heating elements. By reducing sediment accumulation, a Self-Cleaning water heater maintains its rated energy-efficiency longer resulting in consistently low operating costs. Self-Cleaning design also prolongs tank life by helping prevent metal fatigue caused by sediment accumulation at critical weld points.

Types of Water Heaters

Direct-Vent Gas Water Heaters – Draw all air needed for proper combustion from outside the home and vent products of combustion horizontally, through an outside wall. Standard direct-vent water heaters require no electric power and are designed for horizontal venting up to approximately 4 feet from the outside wall and utilize a single two channel vent pipe. By drawing combustion air from the outside, direct-vent water heaters eliminate potential problems caused by inadequate indoor ventilation. And, because they vent horizontally, they are a good choice for many applications where the installation of vertical venting would be impractical or overly expensive.

Flammable Vapor Ignition Resistant (FVIR) Gas Water Heaters – All 30, 40 and 50-gallon State standard-vent gas water heaters are now FVIR design gas water heaters. They are equipped with an advanced system designed to help prevent the accidental ignition of flammable vapors from gasoline and other sources outside the water heater. FVIR design water heaters meet standards for “Flammable Vapor Ignition Resistance” established by ANSI, the American National Standards Institute.

Mobile Home Water Heaters – Gas or electric water heaters designed specifically to meet HUD requirements for manufactured housing installation. A gas mobile home water heater features a gas control that is convertible for natural or propane gas operation. Only water heaters that meet HUD manufactured housing standards can be installed in mobile homes. A standard residential water heater should never be installed in a mobile home.

Point-of-Use Electric Water Heaters – Point-of-use water heaters are designed to serve low-demand applications such as powder rooms, utility sinks and other applications where a limited amount of hot water is required. Small storage tanks (2 through 30 gallons) and compact design permit installation in a cabinet, under a sink, or in other limited-space areas.

Power-Vent Gas Water Heaters – Draw combustion air from indoors like a standard-vent water heater, but permit combined horizontal or vertical vent runs up to 115 feet using inexpensive PVC, CPVC or ABS plastic pipe. Quiet modular blower requires electrical power. Power-vent design provides tremendous flexibility for locating the water heater and vent runs in any home.

Power Direct-Vent Gas Water Heaters – Combine benefits of direct-vent and power-vent water heaters. Utilize two-pipe system, with one pipe for incoming combustion air and a second pipe for venting. Permit combined horizontal and vertical vent runs up to 45 feet, using inexpensive PVC, CPVC or ABS plastic pipe. Quiet modular blower requires electrical power.

Standard-Vent Gas Water Heaters – Also known as atmospheric vent. Draw all air needed for proper burner operation from the indoor air around the water heater and vents products of combustion vertically, through the roof of the home.

Table Top Electric Water Heaters – Feature a rectangular cabinet with a flat surface at 36” height, providing extra useable counter space wherever installed.

Utility Water Heaters – Gas or electric water heaters with high energy factors, which may qualify for special energy-efficiency rebates offered by gas and electric utilities. State Utility water heaters meet Energy Star Home Program recommendations and California Title 24 requirements.

Water Heater Components

Anode Rod – An aluminum or magnesium rod placed inside a gas or electric water heater tank to help protect against corrosion. Often referred to as a sacrificial anode rod because, over time, it slowly dissolves, sacrificing itself as it is attacked by aggressive substances in the water, which would otherwise attack the glass lined steel tank.

Dip Tube – A tube made of high-temperature plastic inserted into the tank through the cold water inlet on top of the water heater. The dip tube extends far down inside the tank so incoming cold water enters near the bottom, where the thermostat, gas burner or primary electric heating element is located.

Draft Diverter – A steel cap placed on top of a standard atmospheric gas water heater centered directly over the flue tube outlet. The vent piping leading out of the water heater is attached to the draft diverter, which helps ensure that products of combustion leaving the water heater are properly directed into the vent piping.

Drain Valve – A plastic or brass valve located near the bottom of the water heater that allows the tank to be drained when the water heater needs to be replaced and also permits periodic partial draining by the homeowner to flush out sediments that may have accumulated in the bottom of the tank.

Electric Heating Elements – The heat source inside an electric water heater, which extends directly into the tank, where it radiates heat energy to the water around it. The water heating power of a heating element is expressed in watts per hour of operation, and State electric water heater wattage ranges from 1440 watts to 5500 watts. Most electric water heaters have two heating elements, one in the bottom of the tank, and one in the top. The bottom element handles most of the load, heating cold water as it enters at the bottom of the tank. The top element only operates to give water in the top of the tank a quick water heating boost when needed.

Expansion Tank – An expansion tank is a small tank designed for installation in the cold water line leading into a water heater. Installation of an expansion tank is highly recommended with every water heater and may be required by code in your area. An expansion tank provides important protection against potential damage to your plumbing system caused by high water pressure, and will help prevent water hammer noises in the pipes. State offers WATERGUARD™ expansion tanks for installation with State and other brand water heaters.

Gas Burner – The heat source inside a gas water heater, the gas burner is a round disk, placed immediately beneath the tank containing water. At the beginning of a heating cycle, gas flows through the burner through multiple ports. This gas is then ignited by the pilot flame or electronic ignition, creating a round pattern of burner flame for even distribution and transfer of heat to the water.

Gas Flue Tube – In a gas water heater, the flue tube is a cylindrical chimney that runs through the center of the tank. Products of combustion from the gas burner rise through the flue tube and leave the water heater, where they are safely discharged to the outdoors through the water heater’s vent piping.

Glass Lining – A coating applied to the inside of a water heater tank to shield the steel from water and help prevent corrosion. The Glass Lining is actually a porcelain compound, sprayed onto all inner tank surfaces and then fired on at very high temperatures, leaving a hard, protective surface.

Hot Surface Ignition – In some gas water heaters (for example, power-vent and power direct-vent models), the constantly-burning pilot flame is replaced by a metallic (silicon nitride) igniter positioned next to the gas burner. When the thermostat calls for a new heating cycle, electricity heats up the igniter surface to a temperature sufficient to ignite the gas. Hot surface ignition is considered an energy-saver, by eliminating the consumption of gas by the pilot flame.

Low-Watt Density and High-Watt Density Heating Elements – A low-watt density electric heating element has a much larger surface area transferring heat to water in the tank. This spreads out the distribution of wattage. For example, each square inch of a 4500-watt low-watt density element is conducting less electrical energy than its high-watt density counterpart. As a result, a low-watt density element operates more efficiently and lasts longer, because its surface simply doesn’t have to work as hard.

Piezo Igniter – A special feature on State FVIR design gas water heater. During installation, or if the pilot flame is extinguished for any reason, the Piezo igniter allows the pilot flame to be re-lit without matches with just the push of a button located outside the water heater.

Consumer Information on new FVIR water heaters from GAMA

Pilot Flame – A small, constantly burning flame positioned next to the gas burner. When the thermostat calls for water heating and gas begins to flow through the burner, the pilot flame ignites the gas causing full burner operation.

T&P Valve (Temperature and Pressure Relief Valve) – An important safety feature, which must be installed on every water heater. In the event of excessive temperature and/or pressure inside the tank, the T&P valve automatically opens to discharge hot water, and help prevent a potentially hazardous condition. All State gas and electric water heaters are equipped with a factory-installed T&P Valve.

Thermostat – In a gas or electric water heater, the thermostat constantly monitors water temperature in the bottom of the tank. When water temperature drops beneath the desired setting, the thermostat signals gas flow or electric heating element operation to begin, starting a new water heating cycle. When water temperature in the bottom of the tank is increased to the desired setting, the thermostat shuts off gas flow or electric heating element operation.

Important Safety Information

Read Your Owners Manual – Before you install or start up your State gas or electric water heater, it is essential that you read and follow all instructions precautions and safety warnings included in your Owners Manual

Flammable Vapors – Gasoline and other common household products (like paint thinner) give off invisible flammable vapors that travel in the air and can be ignited in a number of ways…by an electrical spark, a lighted match, or the pilot flame or burner of a gas appliance.

State FVIR design “Flammable Vapor Ignition Resistant” water heaters are designed to help protect against accidents by containing accidental flammable vapor ignition inside the water heater. There is no substitute, however, for common-sense precautions like…

  • Use gasoline as a motor fuel only, never as a solvent or cleaning agent
  • Always store flammable liquids in approved, properly-sealed containers
  • Never store flammable liquids indoors or within easy reach of children
  • Never store flammable liquids near your water heater or other gas-burning appliance

Tap Water Scald Burns – It is estimated that 4,000 children are scalded by tap water every year, injuries that can leave permanent scars or cause death. These accidents can be prevented by following these common-sense precautions:

  • Before putting a child in the bath tub, test the water temperature with your hand to make sure it’s not too hot.
  • Never leave your child alone, not even for a second. If you need to answer the phone or doorbell, take your child with you.
  • State pre-sets water heater thermostats to deliver a maximum hot water temperature of approximately 120ºF. At this temperature, it takes ten seconds or more to cause a tap water scald burn, even on a child’s sensitive skin. We strongly recommend that you leave your water heater thermostat at the pre-set setting.