How much hot water does a household really need, and what happens when the tank runs out halfway through a shower? A 50-gallon electric water heater is the standard answer for many American homes. The Rheem PROE50-2-RH91 is a tall 50-gallon electric model from the Professional Classic line that runs on 240 volts. This guide explains how a tank water heater works, whether 50 gallons fits your household, and what installation and upkeep involve.
What a 50-gallon electric tank water heater is
A tank water heater stores hot water and keeps it ready. Cold water enters the bottom of the tank, electric heating elements warm it, and hot water leaves from the top when a tap opens. The tank is insulated so the stored water stays hot between uses, and a thermostat watches the temperature and switches the elements on when the water cools below the set point. The PROE50-2-RH91 holds 50 gallons, runs on 240-volt electric power, and comes in a tall shape, which means it is narrower and taller than a short model of the same capacity.
The tall shape matters when you plan the space. A tall 50-gallon tank needs enough ceiling height in the utility closet, garage, or basement where it sits, and it needs clearance above it for the vent or the connections and around it for service access. Measure the space before you buy, including the door the tank has to pass through, since a tank that fits the closet but not the hallway is a problem you discover on delivery day. Also check the floor: a full 50-gallon tank is heavy, and the floor or platform under it has to carry that weight for years.
How an electric tank heats water
Electric tank water heaters usually have two heating elements, one near the top of the tank and one near the bottom. The upper element heats the water at the top first, so hot water is available quickly after the tank has been drawn down, and the lower element heats the bulk of the water over time. The two elements take turns rather than running together, which keeps the electrical load within the rating of the circuit. A thermostat controls each element, and a high-limit switch cuts power if the water ever gets too hot.
When a tap opens, cold water flows into the bottom of the tank and pushes hot water out of the top and toward the tap. The tank refills as it empties, so the heater starts reheating right away. The time it takes to reheat a full tank, called the recovery time, depends on the power of the elements and the temperature of the incoming cold water. In winter, when incoming water is colder, recovery takes longer than in summer. That is normal, and it is one reason a household can run short on hot water on a cold morning with back-to-back showers.
Is 50 gallons the right size
A 50-gallon tank suits many households, but the right size depends on how the house uses hot water rather than on the number of bedrooms alone. Showers are the biggest draw, followed by baths, laundry, and dishwashers. A household where two people shower back to back in the morning uses far less hot water than a household where four people shower, run the dishwasher, and start a load of laundry in the same hour. The peak hour, not the daily total, decides whether the tank keeps up.
As a rough guide, a 50-gallon tank often serves a household of three to five people with ordinary shower habits, but habits matter more than headcount. Long showers, a large soaking tub, and a dishwasher that runs at the same time as the morning showers all push the peak demand up. If the household regularly runs out of hot water, the fix may be a larger tank, a second tank, or a change in habits, such as spacing out showers or running the dishwasher at night. A plumber can estimate the peak-hour demand and say whether 50 gallons covers it.
What 240 volts means for installation
The PROE50-2-RH91 runs on 240 volts, which is the standard supply for electric water heaters in the United States. It needs a dedicated circuit from the electrical panel with the right breaker and wire size, and the circuit must match the rating on the heater's nameplate. Many homes already have a 240-volt circuit where an old electric water heater sat, but the breaker size and the wire have to match the new unit, so the installer checks both rather than assuming the old circuit fits.
Electrical work on a water heater is a job for a licensed electrician or a plumber licensed for that work, and most areas require a permit and an inspection. The installation also needs a cold-water shutoff valve, a temperature and pressure relief valve with a discharge pipe that runs to a safe drain point, and, in many areas, an expansion tank on the cold-water line. The relief valve is a safety device, not an optional extra: it opens if the pressure or temperature in the tank climbs too high, and its discharge pipe must run somewhere the hot water can go without scalding anyone or flooding the house.
Where to put the tank
Placement is about access, drainage, and damage control. The tank needs room around it for service, clearance above it for the connections, and a location where a leak will be noticed quickly. A drain pan under the tank, piped to a floor drain or to the outside, catches slow leaks before they soak a floor. In a garage, the tank needs protection from vehicle damage and, in cold climates, from freezing. In an attic or an upper floor, a leak can damage the rooms below, so the pan and the drain matter even more.
Think about the distance to the taps as well. The farther hot water has to travel through pipes, the longer you wait for hot water at the tap and the more water runs down the drain while you wait. A tank placed near the bathrooms and the kitchen wastes less water and delivers hot water faster. If the tank is far from the taps, a recirculation loop or a point-of-use heater at the far tap can help, but those are separate decisions with their own costs. Talk through placement with the installer before the old tank comes out.
Setting the temperature
Most households set the thermostat somewhere between 120 and 140 degrees Fahrenheit, and the choice is a balance between comfort, safety, and energy use. Water at 120 degrees is hot enough for showers and dishwashing in most homes and uses less energy than water kept at 140 degrees. Water stored at higher temperatures carries a scald risk, especially for children and older adults, and a mixing valve at the tap can blend in cold water to make the delivered temperature safer while the tank stays hot enough to meet demand.
Do not set the temperature below 120 degrees to save energy. Water kept too cool can allow bacteria to grow in the tank, and the small saving is not worth the risk. If the household needs more hot water than the tank delivers, raising the temperature a few degrees and fitting a mixing valve is one option, but it is better to check the tank size and the peak-hour demand first. Set the temperature, wait a day, and test the water at the tap with a thermometer before deciding whether to adjust it again.
Routine maintenance
A tank water heater needs a little regular attention to last its full service life. Once a year, test the temperature and pressure relief valve by lifting its lever briefly and making sure water flows out of the discharge pipe and the valve closes again without dripping. Drain a few gallons from the bottom of the tank through the drain valve to flush out sediment, since sediment builds up on the bottom, insulates the lower element, and makes the heater work harder and noisier. In areas with hard water, sediment builds up faster, and flushing matters more.
Every few years, have a plumber check the anode rod, which is a metal rod inside the tank that corrodes in place of the tank lining. When the rod is worn away, the tank itself starts to corrode, and a tank that could have lasted years longer fails early. Replacing a worn anode rod is cheap compared with replacing a tank. Also check the area around the tank now and then for dampness, rust, or a dripping relief valve, since a small leak caught early is a repair and a leak found late is a flooded floor.
Questions to ask your installer
Ask the installer to confirm the tank size against the household's peak-hour hot water use, and ask whether the existing circuit, breaker, and wire match the new heater. Ask what the price includes: the tank, the pan, the relief valve and discharge pipe, the expansion tank if required, the electrical work, permits, and haul-away of the old tank. Ask how the old tank will be drained and removed, since a full 50-gallon tank is heavy and awkward to move through a house.
Also ask about the warranty on the tank and the elements, and whether the installer handles warranty claims or leaves that to you. Ask where the shutoff valve and the breaker are, and have the installer show you how to test the relief valve and how to drain the tank. Write down the model number, the serial number, and the install date, and keep them with the warranty paperwork. Those details come up whenever you call for parts or service, and having them ready saves time.