Best Tankless Water Heater Service Companies in Hawaii Ranked

Upgrading to a tankless water heater in Hawaii is a smart move for homeowners seeking endless hot water, lower energy bills, and valuable space savings. These on-demand systems provide hot water only when you need it, making them exceptionally efficient for island living. This guide explains the key considerations for installing and maintaining a tankless system in Hawaii, from choosing the right fuel type to navigating local codes, so you can make an informed decision and connect with qualified local specialists for your project.

Roto-Rooter Plumbing & Water Cleanup

2106 Lauwiliwili St Ste 101j, Kapolei, HI 96707

Roto-Rooter Plumbing & Water Cleanup offers comprehensive residential and commercial plumbing services in Honolulu, HI. Their experienced team handles a wide range of plumbing needs, including sewer line inspections and repairs, water heater installation and repair, drain cleaning, leak detection, and gas line installation. They specialize in trenchless sewer repair and provide emergency plumbing services available 24/7 throughout the year. With expertise in floodwater cleanup and mold remediation, Roto-Rooter is equipped to manage urgent water damage situations efficiently. Serving Kapolei and surrounding communities, they combine local knowledge with advanced tools like hydro jetting to address plumbing challenges effectively.

4.9

1.5k Reviews

Shoreline Plumbing

honolulu

Shoreline Plumbing is a locally owned plumbing company serving Honolulu, HI, and surrounding Oahu communities. They offer a wide range of plumbing services including water heater installation and repair, drain cleaning, sewer line repair, leak detection, and fixture upgrades. The team specializes in both traditional and tankless water heaters, providing thorough inspections and reliable repairs to maintain home comfort. Shoreline Plumbing also handles sewer line assessments and root intrusion solutions to keep plumbing systems flowing smoothly. Their approach emphasizes clear communication, honest pricing, and long-lasting results, aiming to prevent recurring plumbing issues rather than quick fixes.

4.9

267 Reviews

Roto-Rooter Plumbing & Water Cleanup

3049 Ualena St Ste 713, Honolulu, HI 96819

Roto-Rooter Plumbing & Water Cleanup provides comprehensive plumbing services in Honolulu, HI, serving both residential and commercial customers. Their experienced plumbers handle a wide range of issues including sewer and drain cleaning, water heater repair and installation, leak detection, sewer line repair with trenchless methods, and water damage cleanup. The company is familiar with Honolulu's unique plumbing challenges such as aging infrastructure and weather-related impacts. Roto-Rooter offers 24/7 emergency plumbing services to address urgent problems like burst pipes, sewer backups, and flooding. They also provide advanced capabilities like hydro jetting and trenchless sewer repair to efficiently restore plumbing systems. Serving Honolulu and surrounding communities on O'ahu, Roto-Rooter is fully licensed and insured. Their team uses modern tools and techniques to comply with local codes and ensure effective solutions. The company is available around the clock, 365 days a year, for emergency plumbing needs.

4.8

2.1k Reviews

Malama Drains “Rooter & Drain Cleaning”

honolulu

Malama Drains "Rooter & Drain Cleaning" provides plumbing and drain cleaning services in Honolulu, HI. They offer a range of solutions including drain cleaning, sewer camera inspections, water heater installation and repair, leak detection, and sewer line repairs. The company uses advanced equipment such as hydro-jetting and video cameras to diagnose and clear plumbing issues efficiently. Malama Drains is locally owned and operated, serving the community with eco-friendly practices and a commitment to customer care. They also provide 24/7 emergency plumbing services for urgent repairs.

5.0

43 Reviews

Cubellis Plumbing LLC

honolulu

Cubellis Plumbing LLC is a family-owned and operated licensed plumbing contractor serving Honolulu, HI. With over 20 years of experience, they provide a wide range of plumbing services including water heater repair and installation, leak detection, repiping, gas line installation, and garbage disposal repair. As a member of the Moen Plumber Network, they specialize in installing Moen Smart Water products and offer island-wide service. Cubellis Plumbing also provides extended services during weekends, holidays, and after hours. Their expertise includes tankless water heater repair and gas water heater services.

5.0

29 Reviews

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Why Choose a Tankless System in Hawaii?

Tankless, or on-demand, water heaters are an excellent fit for many Hawaiian homes. Unlike traditional tank models that constantly heat and reheat a stored volume of water, tankless units heat water directly as it flows through the device. This eliminates standby heat loss, which can account for a significant portion of a traditional water heater's energy use. For households concerned with efficiency and reducing their environmental footprint, this is a major advantage.

The compact size of a tankless unit is another benefit, especially in homes where utility closet or garage space is limited. You can mount them on an exterior wall, in a crawlspace, or in other out-of-the-way locations. Most importantly, you'll never run out of hot water during a shower, as the system provides a continuous supply. However, proper sizing is critical to ensure the unit can meet your household's simultaneous hot water demands, such as running a shower and a dishwasher at the same time.

Fuel Types: Electric vs. Gas in the Islands

The first major decision is choosing between an electric or gas-powered tankless water heater. Each has specific requirements that impact installation complexity and cost.

Electric Tankless Water Heaters are common in Hawaii. They are generally simpler to install as they don't require venting for exhaust gases. However, they have a significant electrical demand. Installing an electric on-demand heater often requires upgrading your home's electrical service panel to add a dedicated, high-amperage circuit ^{1 2}. The unit must be properly wired and grounded to handle the substantial load. For older homes, this electrical upgrade can be a considerable part of the project cost.

Gas Tankless Water Heaters (which can use natural gas or propane) are powerful and can often support higher flow rates for larger homes. The installation is more complex, as it involves gas lines, combustion air supply, and a dedicated venting system to safely exhaust fumes ^{1 3 4}. Venting must be made of approved materials like stainless steel and routed according to strict code requirements. If your home doesn't have an existing gas line of sufficient capacity, running a new line adds to the project's scope and expense.

Understanding Installation Steps and Requirements

Professional installation is highly recommended for tankless water heaters. It ensures safety, compliance with Hawaii's building codes, and protects the manufacturer's warranty. Here's an overview of the typical installation process conducted by a licensed professional:

1. Home Assessment and Permitting: A qualified technician will evaluate your home's capacity-checking electrical panels or gas line size-and determine the correct unit size (measured in gallons per minute, or GPM) for your needs. They will also pull any required local building permits ^{1 5}.
2. Selecting the Location: The unit must be installed near the main points of water use to minimize heat loss in the pipes. It requires adequate clearance for maintenance and, for gas models, proper ventilation space. In many Hawaii locations, a drain pan may be required to prevent water damage from potential leaks ^{1 6}.
3. Utility Shutoff and Preparation: The installer will shut off the home's water supply, electricity, and gas (if applicable) before removing the old water heater and preparing the site.
4. Mounting and Plumbing: The tankless unit is securely mounted to a sturdy wall or surface. New water lines are connected for the cold water inlet and hot water outlet, often including shut-off valves and, in some cases, a water softener if local water hardness is high.
5. Connecting Fuel and Power: For gas models, a licensed professional will connect the gas line with a drip leg and test for leaks. For electric models, a licensed electrician will run the dedicated circuit and make the final connections ^{2 3}.
6. Venting (Gas Models): An approved venting system is installed to direct combustion gases safely outdoors. This is a critical safety step that must follow manufacturer and code specifications ¹.
7. System Startup and Inspection: The system is flushed, tested for leaks, and started up to ensure proper operation. A final inspection by the local building department may be required to close the permit ^{7 8}.

Hawaii-Specific Codes and Considerations

Installing a tankless water heater in Hawaii must comply with the state's adopted building codes, primarily the Hawaii Residential Code. Key considerations include:

• Accessibility: The code requires that all water heaters be installed in a location that allows for observation, maintenance, servicing, and replacement of the unit ⁶. This means they cannot be sealed behind permanent walls or installed in inaccessible attics without proper access panels.
• Drain Pans: In installations where a leak could cause damage to the interior of the building, the code often requires a drain pan under the unit. The pan must be piped to an approved drainage location ⁶.
• Venting and Electrical: Gas venting must be designed for Category III appliances and properly supported. Electrical connections must be rated for the load and protected appropriately. These rules are in place to prevent fire and carbon monoxide hazards ^{1 6}.

Working with a licensed plumber who is familiar with these local amendments is essential for a safe and legal installation.

Cost Overview for Installation in Hawaii

The total cost for a tankless water heater installation in Hawaii can vary widely based on the unit type, your home's existing infrastructure, and labor rates. Here is a general estimate breakdown:

• Unit Cost: The price of the tankless heater itself ranges from a few hundred dollars for a basic electric point-of-use model to over $2,000 for a high-capacity whole-home gas unit ^{7 9}.
• Basic Installation Labor: Labor for a straightforward replacement in a location with all necessary utilities already in place can range from $800 to $1,500 or more ^{7 5}.
• Required Upgrades (Major Cost Drivers): Most of the cost variability comes from necessary upgrades. This includes upgrading an electrical panel ($1,000-$3,000+), running a new gas line ($300-$2,000+), or installing complex venting for a gas unit ^{7 8 10 11}.
• Total Installed Cost: When combining the unit, labor, and any required upgrades, homeowners in Hawaii can expect a total investment ranging from approximately $1,500 on the very low end for a simple electric retrofit to $5,000 or more for a complex gas installation requiring significant new infrastructure ^{7 5 9 11}.

Maintenance and Common Repairs

To protect your investment, regular maintenance is crucial. An annual flush of the system to remove mineral scale (especially important in areas with hard water) will maintain efficiency and extend the unit's lifespan. Many local plumbing companies offer specific maintenance plans for tankless systems ¹².

Even with good maintenance, components can fail. Common repair costs include:

• Replacing a fuse or fixing a vent issue: $50 - $125 ¹²
• Repairing or replacing a thermostat or valve: $75 - $150 ¹²
• Repairing internal piping or heat exchanger issues: $100 - $350+ ¹²

Prompt attention to error codes or changes in performance can prevent small issues from becoming major, costly repairs.

Frequently asked questions

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