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Tankless Water Heater Installation Across Hawaii

Fast, reliable service, done right the first time.

Hot water that does not run out and no tank to reheat. All Aloha Plumbing sizes and installs tankless units on Oahu, Maui and the Big Island.

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A storage tank heats 40 to 50 gallons of water around the clock, whether anyone is home or not. A tankless water heater fires only when you open a hot tap and heats the water as it passes through. If your tank runs out partway through the second shower, takes up closet or garage space, or keeps adding to a high electric bill, a tankless system is worth a look. All Aloha Plumbing installs tankless water heaters in homes on Oahu, Maui and the Big Island.

Why Tankless Makes Sense in Hawaii

Electricity costs are high across the islands, so wasted energy shows up on the bill more than it would on the mainland. A tank loses heat through its walls all day, which is called standby loss, and then uses power to reheat that same water. A tankless unit avoids most of that loss because it only runs on demand.

There are other practical gains. With no tank, there is no risk of a sudden tank rupture flooding a garage or utility closet, and wall-mounted units free up floor space. Tankless units also tend to last longer than tank models when they are maintained.

Sizing and Fuel: Getting It Right

A tankless unit only works well if it is matched to your peak demand. We count the fixtures and appliances that may run at the same time, such as two showers and a dishwasher, and select a unit with a flow rate that covers that load. For very large homes, more than one unit may be the better setup.

We also look at fuel. Gas units need proper venting and an adequate gas supply. Electric units often need a larger electrical circuit. A straight swap can be quick, while a tank-to-tankless conversion with new venting, gas or electrical work takes longer and may require a permit. We explain all of it before you decide, with upfront pricing approved before work starts.

Tankless Installation by Island

  • Oahu: From Honolulu condos with limited closet space to family homes in Mililani, Kapolei and Kaneohe, we fit the unit to the space and the building. See tankless water heater installation on Oahu.
  • Maui: Vacation rentals in Kihei, Wailea and Lahaina often have back-to-back guests using hot water at once, so correct sizing matters. Upcountry homes in Pukalani and Kula have their own layouts. Learn about tankless water heater installation on Maui.
  • Big Island: Homes from Kailua-Kona to Hilo and Waikoloa vary widely, and some rural properties run on rainwater catchment, which affects filtration and maintenance planning. Read about tankless water heater installation on the Big Island.

What Every Installation Includes

  • An assessment of your hot water use, plumbing, venting and electrical or gas supply.
  • A clear recommendation on unit size and fuel type.
  • Code-compliant installation by licensed plumbers.
  • Removal and disposal of the old water heater.
  • Full testing and a walkthrough on operation and routine flushing.

All Aloha Plumbing is family-owned, licensed and insured under Hawaii contractor license CT-36812. We currently offer $100 off water heater installation, plus senior and military discounts, and financing is available.

Plan Your Tankless Upgrade

To get started, visit your island page for Oahu, Maui or the Big Island. If you are without hot water today, call the number at the top of this page. A real plumber answers 24/7.

Need Tankless Water Heater Installation on Hawaii?

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Quick Answers

Good To Know

Do you install tankless water heaters on every island you serve?

Yes. All Aloha Plumbing installs tankless water heaters on Oahu, Maui and the Big Island. Our Oahu team is based in Waipahu, our Maui team is based in Makawao, and we serve the Big Island across communities like Kailua-Kona, Hilo, Waimea and Waikoloa, with arrival windows based on location.

Is a tankless water heater a good fit for a Hawaii home?

For many homes, yes. Because electricity costs are high in Hawaii, the standby heat a storage tank loses all day costs more here than in most places. A tankless unit heats water only on demand. The right answer depends on your usage and setup, so we review both before recommending a unit.

What size tankless unit does my home need?

Size is based on peak demand, not the number of bedrooms. We add up the fixtures and appliances that may run at the same time and choose a unit with enough flow rate to cover them. For large homes or rentals with heavy simultaneous use, we may recommend two units instead of one.

Can I switch from a tank to a tankless water heater?

In most cases, yes. Depending on your home, the switch may need new venting, a larger gas line or an upgraded electrical circuit. That work can add time and may require a permit. We assess your current setup first and give you upfront pricing that covers everything the conversion needs.

How long does a tankless installation take?

A simple replacement of an existing tankless unit can often be done in a day. A full conversion from a storage tank that needs venting, gas or electrical changes takes longer. After we look at your home, we give you a clear timeline along with upfront pricing before any work begins.

What maintenance does a tankless water heater need?

Plan on periodic flushing to remove mineral buildup from the heat exchanger, along with routine checks of the burner or heating elements, sensors and venting. Homes on rainwater catchment may also need attention to filtration. Regular service keeps the unit efficient and helps it reach a long service life.

Real Customers • Real Stories

What Our Ohana Says

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“All Aloha came out super fast and fixed our leak the same day. Excellent service! These guys are real pros and treated my home with respect.”

HBM

Hawaii Bottle Man

Honolulu, Oahu

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“They replaced our water heater quickly and left everything spotless. The crew showed up exactly when they said they would. Couldn’t ask for better.”

RC

Ray Cabanting

Kailua, Oahu

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“Called at midnight with a burst pipe. They were here in 25 minutes and had it contained before the ceiling came down.”

TT

Thai Tran

Kapolei, Oahu

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Three Islands. One Family.

From the North Shore to Hilo, we’re proud to bring honest plumbing with aloha to homes across Hawaii.

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