Water Heater Questions and Answers
What is the average lifetime of a gas water heater?
The average lifetime of gas water heater is 9 years. The range is 5-14 years.
When I am in the laundry room and the water heater is operating, I hear a rumbling sound coming from the water heater. What could cause this?
Rumbling sounds coming from a water heater are an indication that sediment has built up on the bottom of the water heater. What you are hearing is water that is trapped in the sediment and is boiling. This is an indication that the water heater is not operating efficiently. Sediment will not allow the heat to transfer to the water in the tank, which sends the heat up the flue. You may try draining a few gallons of water off the bottom of the water heater tank. This is done by attaching a drain hose to the valve at the bottom of the tank. Allow it to drain for about five minutes.
WARNING: HOT WATER IS DANGEROUS. DISCHARGE THE WATER INTO A FLOOR DRAIN, LAUNDRY TUB OR BATHTUB. HOT WATER WILL KILL YOUR GRASS IF DISCHARGED ONTO THE LAWN. HOT WATER WILL CRACK A TOILET BOWL IF DISCHARGED INTO THE TOILET.
Many newer models of water heaters have a new feature that prohibits the buildup of sediment in the tank. If your heater is an older model, it may be cost effective to replace the water heater if the buildup is severe.
Why doesn’t my old water heater work as well as it used to?
This is usually due to a sediment buildup in your tank. As water heaters grow older, they accumulate sediment and lime deposits. If these deposits are not removed periodically, the sediment will create a barrier between the burner and the water, greatly reducing the water heater’s performance level. Draining the heater on a regular basis helps remove the sediment. At least once every year, drain all of the water from the tank.
You should also periodically inspect your water heater burner. The flame under the heater should appear blue with yellow tips. If it’s mostly yellow, or if it’s sooty under there, your flue may be clogged, which is a dangerous situation. Contact us to check it out. At least once every year, have your water heater inspected by a service technician. The technician will also check the drain valve for signs of leakage, and the anode rods for corrosion.
How is FHR and Therms used to compare the efficiency of water heaters?
The first hour rating (FHR) tells you the number of gallons per hour of hot water. Therms relate to the gas consumption of water heater. When you are shopping for hot water heater, compare the energy factor on the energy guide label. FHR and Therms are not sufficient to calculate the energy factor. Also remember to compare water heaters of equal capacity and FHR.
What efficiency standard does a dual use residential water heater need to meet as a water heater or a boiler considering being used for both potable water and space heating purposes?
For a dual unit, it must meet the efficiency standard requirements of both applications. Your local building department may have additional requirements for such units.
What is a hot water recirculating system?
A “hot water re-circulating” system usually refers to a domestic hot water system that circulates the heated water through the house continuously so as to eliminate or shorten the delay in hot water reaching the faucet after the user turns it on. These systems are most common in multifamily or large building applications where otherwise the delays would be truly unacceptable. They can be require a great deal of energy if the pipes aren’t well insulated.
How do I choose the best electric or gas tankless water heater for my 3,500 sq. ft. home?
Sizing of hot water heaters should not be based on the size of the house. The most important factor are the number of occupants and their peak hour water demand.
Are tankless water heaters more efficient?
Tankless water heater efficiencies are not addressed by the Federal standards. Check the EREC fact sheet at http://www.eren.doe.gov/consumerinfo/refbriefs/bc1.html for additional resources.