What size water heater do I need?

Common questions

What size water heater do I need for a family of four?

Most four-person households are correctly served by a 50-gallon gas tank or a 75-gallon electric one. The reason the electric is bigger is recovery: a gas burner reheats roughly 36 gallons an hour against about 20 for a standard electric element, so electric needs more stored water to cover the same morning. If your four people shower one after another inside an hour rather than spread out, size up.

Does a 50-gallon tank actually give me 50 gallons of hot water?

No. You get roughly 70 percent of the nameplate capacity as genuinely hot water, so about 35 gallons from a 50-gallon tank. As the tank draws down, cold inlet water mixes with what is left and the delivered temperature falls off well before the tank is empty. This is the single most common reason a household that "sized correctly" still runs out.

Tank or tankless — which is better?

Tankless never runs out but is limited by flow, and a tank holds a fixed amount but can serve several fixtures at once. A tankless unit suits a household that runs out of hot water rather than one that needs a lot at the same moment, and it wants a correctly sized gas line, its own venting, and descaling roughly once a year. A tank is cheaper to install, tolerates hard water better, and is usually the right answer when the existing one simply failed. In Bergen County the deciding factor is often whether the gas supply and venting can be adapted without opening walls.

How long does a water heater last?

A conventional tank generally lasts 8 to 12 years and a tankless unit can run 20 years or more with annual descaling. Water quality is the biggest variable: sediment and scale shorten tank life considerably, and a tank that has never been flushed will fail earlier than one that has. Once a tank passes ten years, plan the replacement rather than waiting for the failure.

What temperature should I set my water heater to?

120°F is the standard recommendation and the right setting for most homes. It is hot enough to be useful, reduces the risk of scalding — which matters with small children or older adults — and costs less to maintain than a higher setting. Going much below 120°F is not advisable, because the cooler water inside the tank becomes more hospitable to bacteria. If you need hotter water for a specific appliance, the better answer is a mixing valve rather than turning the whole tank up.

What are the signs my water heater is about to fail?

Rusty or brown hot water, a rumbling or popping noise, water pooling at the base, and hot water running out sooner than it used to are the four signs worth acting on. The rumbling is sediment that has built up on the bottom of the tank; rust-coloured water means the inside of the tank is corroding. Water at the base of the tank is the one that is not repairable — once the steel jacket has gone, the unit has to be replaced.

Can I just replace my water heater with the same size?

Often yes, but it is worth checking rather than assuming. Households change — a finished basement bathroom, a new soaking tub, a teenager who takes long showers, or a switch to a high-efficiency washer all move the number. A like-for-like swap is also the moment to find out whether your current tank was correctly sized in the first place, since most people inherit whatever the previous owner installed.

Why does my hot water run out faster in winter?

Because the water arriving at your house is colder, so the heater has to raise it further and takes longer to recover. In northern New Jersey incoming water sits near 50°F in winter, meaning a 70-degree rise to reach a 120°F setting, where in summer the same heater might only need to lift it 40 degrees. The same tank genuinely delivers less hot water in January than it does in July, and it is the usual explanation for a heater that seemed fine until the cold weather arrived.