Posted on January 30, 2024
Water Heater Thermostats
Water heaters provide hot running water for showering, washing clothes, dishes, and other household activities. They use electricity, gas, or fuel oil to heat the water.
They typically have a large storage tank and use the principle that heat rises to ensure you always have plenty of hot water. Look for tanks with glass linings to prevent corrosion and brass drain valves that last longer. Click Here to learn more.
The thermostat controls the heating element that turns on and off to heat your water. It reads the temperature of the hot water entering the tank and tells the heating element when to start and stop. Using a water heater thermostat that has been correctly set for your hot water usage can save you money by reducing energy consumption. A programmable thermostat can also enable you to schedule a timed heating cycle at off-peak electricity rates, saving even more money.
To check your thermostat, first shut off power to your electric water heater at the circuit breaker box so you can work safely. Next, remove the access panel covers and any insulation from the upper and lower thermostats. You may need to use a screwdriver to open the access panels.
After opening the access panels, turn on your multimeter to test continuity of the upper thermostat by placing one lead on the thermostat terminal and the second lead on the lower heating element terminal. The meter should read close to zero ohms of resistance. If the meter reading is opposite of this, the thermostat is not functioning properly and will need to be replaced.
A water heater’s thermostat is designed to prevent damage by switching off the heating elements when the temperature of the water in the tank rises above a designated setting. This is important because constant heating consumes large amounts of electricity, and a defective thermostat can lead to overheating that causes damage to the elements and to the water heater itself.
A water heater’s thermostat can be manually reset by pressing a button that appears through the access panel cover. Some gas water heaters have a thermostat-reading probe that protrudes into the water tank. When the temperature of the water drops below a thermostat setting, the gas valve opens to release gas into the combustion chamber. A dirty, sooted or obstructed probe and burner can cause gas to build up until it reaches the pilot flame, which can cause a hazardous explosion. Often, the problem is simply caused by an inaccurate thermostat reading or a malfunctioning sensor.
The size of your tank, or capacity, is another key factor when deciding on the right water heater for your home. A water heater with a tank that is too small will not be able to keep up with your household’s demand for hot water, especially during peak usage hours when showering and washing laundry happen. The water heater will need to run constantly in order to keep up with demand, which can lead to higher energy bills and premature wear and tear on the unit.
Traditional storage tank water heaters typically range in size from 20-80 gallons and can be heated by electricity, propane gas, natural gas or fuel oil. A water heater’s tank size should be based on the household’s peak hour use in order to ensure there is enough capacity for a full day of hot water demand.
To determine the proper tank size for your household, you will need to figure out how many people are living in your house and when your busiest hour of hot water use occurs. For example, it may be the morning when two people take showers back to back, or it could be the evening when everyone runs their dishwasher and takes a shower. Once you have identified your household’s busiest hour of hot water usage, you can then begin to calculate how many gallons of water you need each day.
Showering uses around 6 gallons of water, washing a load of laundry uses about 14 gallons, and running the dishwasher can use up to 30 gallons. Once you have calculated the number of gallons per person that you need each day, you can then add up your total daily usage and compare it to the tank sizes available in order to make the best purchase decision for your home.
When calculating the optimum tank size for your home, you should also consider your climate, as temperatures can affect the amount of energy needed to heat water. For example, a hot water heater in the North will need to have a higher BTU rating to heat water up to a comfortable temperature than one in the South.
The water heater is the second largest source of energy consumption in most homes. That’s why it’s important to select the most efficient model you can afford. Energy efficiency ratings, found on the bright yellow EnergyGuide label, are a useful tool for comparing models. These ratings are based on recovery efficiency, standby losses, and cycling heat loss. The higher the EF, the more energy your system uses efficiently.
Energy efficiency is also impacted by the type of fuel used to power your water heater. Gas water heaters use natural gas or propane and operate more efficiently than electric resistance models. They can also save you money when natural gas prices are lower than electricity rates.
A hot water heater’s efficiency is also impacted by the size of its tank and piping. Insulating the water heater’s tank and pipes can reduce heating losses by retaining more of the stored heat. Smaller, wider-diameter piping with fewer elbows can reduce energy usage as well.
High-efficiency electric water heaters (HEWH) use up to 65% less energy than standard units. This can significantly reduce your utility bills. HEWHs with smart thermostats can initiate heating at off-peak hours when electricity costs are lowest. Some can even run a high-demand auxiliary feature, which heats water on demand at the time you need it.
Another energy-saving option is a solar water heater, which uses a roof-mounted cell to capture and store the sun’s heat in an antifreeze-like solution that runs to the water tank. These systems deliver stellar savings in warm, sunny regions.
If you’re looking for a new water heater, look for the UEF rating on the EnergyGuide label. This is a more realistic and accurate representation of the energy-efficiency performance of a water heater based on updated testing procedures. Also look for First Hour Delivery (FHR), which indicates how much hot water a unit can supply in its first hour of operation. A low FHR could be a sign of a less-efficient unit. However, it’s possible to substantially increase a water heater’s FHR through water conservation efforts. Often, the increased efficiency of a new unit will pay for itself in just a few years through lower utility bills.
The water heater is one of the most neglected appliances in a home. However, it’s not difficult to perform some simple maintenance on a regular basis. This can help prevent problems down the road, like a costly or destructive leak.
Inspecting your water heater on a monthly basis can alert you to leaks, worn gaskets and loose screws before they cause serious damage. In addition, flushing the tank about twice a year helps increase the longevity and efficiency of your unit.
Most water heater leaks are caused by faulty connections, so inspecting the connections on your unit on a regular basis is a good idea. If you see rust on the connection pipes, it may be time to replace them. Leaks from the temperature and pressure relief valve discharge pipe are another common problem that can be prevented with a little preventative work.
While it might seem scary to get close to your water heater, a basic understanding of how your unit works is all you need to keep it running well. Water comes into the tank from the incoming cold water line and is heated by a heating element inside. The warm water then flows out of the top of the tank through a metal drain pipe and into your home plumbing system.
Minerals in the water that enters your tank can build up and form a layer of sediment in the bottom of the tank, reducing efficiency and capacity. Over time, the sediment can also block the drainage and pressure valves, causing irreparable corrosive damage to your unit.
In addition to regularly flushing and checking your pressure valves, you should replace your sacrificial anode rod every four years. It’s easy and inexpensive to do, but the rod will only corrode before it has nothing left to give, leaving your tank vulnerable to damaging corrosion.
Lastly, most gas and electric units have a safety device called a pressure relief valve, which is designed to automatically release water or steam in case of overpressure. This valve is easily accessible, located on the tank and typically has a toggle switch with an open piece of pipe extending down towards the floor.