What size wire for water heater?

What Size Wire Is Needed For An Electric Hot Water Heater?

water heater

A 30 to 40 amp water heater needs a 8-gauge wire, a 25-amp water heater needs a 10-gauge wire, and a 20-amp water heater needs a 12-gauge wire. It is best to use a wire that is larger than needed when you are going to wire a water heater. Water heaters come in different sizes and need different wire sizes for each.

Depending on the size and amperage of your water heater, here are some different wires available on amazon.

What is a water heater?

types of water heaters

A water heater is a device inside homes or building that takes in regular temperature water from the city or whatever means of sourcing water and heats it up for safe use with said homes or buildings.

Check out this Propane Tankless Water Heater from amazon. It has mnany 5 star reviews.

Different types of water heaters

There are mainly 5 different types of water heaters. Each has their own pros and cons. Below i will go over each f these types.

  1. Conventional Storage Tank Water Heater
  2. This design of hot water heater includes a storage tank that holds a certain amount of water to be warmed or heated. The available hot water at any time is dependent on the size of the water heater. The container is shielded to ensure that when the water warms up, it stays hot till it is required. This container includes 2 shutoffs, the temperature level control shutoff, and also the stress control shutoff. The temperature level control shutoff opens up to let out some heat when the temperature level gets to over 120 degrees. The stress control shutoff open up to reduce the stress when it gets to around 150 psi. This is one of the most popular type of hot water heater amongst homeowners, however you are restricted to just how much warm water your heater can hold. The one harsh downside to this type of water heater is that whenever you need lots of hot water on a specific day, you might run out and have to wait for the new tankful to heat up.

    • This type of water heater is easy to install
    • Usually cheaper than other types of water heaters
    • Set amount of water storage
    • Long wait time to heat up added water
  3. Heat Pump Water Heater (Hybrid Water Heater)
  4. This water heater is one that uses nature to heat water. It takes heat from the ground and air and only then is electricity used to transfer the heat it into the water that needs to be heated.

    • Uses less electricity than most other water heaters
    • Saves money in the long run
    • Climate plays a role in how much heat can be produced
    • Expensive to set up
  5. Tankless Water Heater (On-Demand Water Heater)
  6. The tankless water heater has no tank. It uses super-heated coils that collects water and heats it up in an instant for use. This is why it is usually called an on-demand water heater. These come in different sizes and is great for large families. They are best suited for homes that use gas to run and are better off with homes that have large gas lines. Some tankless water heaters use electricity as a means to run, but these types of tankless water heaters usually use a lot of energy. Therefore, some homeowners might need to upgrade their electrical capacity in order to safely run.

    • Uses less electricity than most other water heaters
    • Expensive to setup
  7. Condensing Water Heater
  8. The condensing style water heater is best suited for homes that mainly use natural gas as it's main source of energy. Water is heated by the funneled exhaust from the natural gas system. The condensing water heater uses small amount of energy as it mainly uses exhaust produced from users using items such as stoves or an oven. When purchasing one of these types of water heaters, be sure to purchase a large one as these are tank style water heaters.

    • Great for families that mainly use natural gas
    • Holds lots of water dep[ending on the size you purchase.
    • Best for large families as small tank are not readily available.
    • Not good for homes that don't use natural gas.
  9. Solar Powered Water Heater
  10. These types of water heaters are getting more popular as the years go by. This type of water heater relies on heat energy from the sun to heat the water. This is usually done by mounting solar panels on your roof and adding a conductive material to your tank which in turn heats the water in it. This water heater is great for sunny climate but will need a backup source of energy in colder areas. This is why people who own solar powered water heaters usually have a backup plan in the form of electricity or propane.

    • Uses less electricity than other water heaters
    • Environmentally friendly
    • Saving realized every month over electric water heaters
    • Expensive to set these types of water heaters up.

Features to consider when buying a water heater

Buying a water heater is just like buying any other important item for your home. You have to think about certain things like the cost, size, and warranty. Below i will go over some of the things to consider when purchasing one of these water heaters.

  • Type of warranty
  • Just like buying a new car, you need to check what type of warranty you will be getting when you purchase your water heater. Water heater warranty is usually offered at 3 - 12 years coverage. Be prepared to pay a little more to get the 12 year coverage.

  • Plastic drain Valves vs. Brass Drain Valves
  • These valves are situated at the bottom of water heaters that allow you to drain the water heater with a regular garden hose. It is wise to get the brass type drain valve as it is more durable.

  • Digital Display types
  • It is easy to check water levels and water temperatures when you have a digital display. This option takes all the guess work out of owning a water heater.

  • Tank Size
  • Think about the size water heater that is right for you or your family. You should choose a tank size that will easily supply your family with enough hot water each day.

  • Glass-lined tanks
  • These types of tanks are built to last as they protect your tank from corrosion.

What size breaker for an electric water heater?

A regular electric water heater needs 240 volts of continuous power. A 30-amp double-pole breaker is needed to carry this amount of voltage safely to the electric water heater.

What happens if you wire a water heater backwards?

If you wire a water heater backwards then you won't get as much of a hot water as you should as the hot water will be running through the bottom while the cold water will be at the top. OIf you wire your water heater correctly, hot water will be at the to and cold water at the bottom.

What size breaker for a 40 gallon electric water heater?

On a typical 40 or 30 gallon water heater, a 30 amp breaker is usually used.


So what size wire is used for an electric water heater? The answer is simple. Depending on the amperage of your water heater, you might need a 8 gauge wire, a 10 gauge wire, or a 12 gauge wire.

How to wire 30 Amps

Here i go over how to wire a 30 amp rv outlet.


About Author:

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Hi, I'm Kevin Pommells, a lover of camping and the great outdoors as everyone says nowadays. I'm also a passionate soccer fan and the proud owner of CamperRules.com, a website dedicated to helping campers and outdoor enthusiasts make the most of their adventures. With years of experience exploring the wilderness and a deep love for the sport of soccer, I'm always looking for new ways to combine my two passions and share my knowledge with others. Follow me for tips, tricks, and insights on all things camping and outdoor recreation.

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