Eccotemp Scratch & Dent - Builder Series 6.5 GPM Indoor Natural Gas Tankless Water Heater - 1779607510022_702

Eccotemp Scratch & Dent - Builder Series 6.5 GPM Indoor Natural Gas Tankless Water Heater - 1779607510022_702

The Eccotemp 6.5 GPM Indoor Natural Gas Tankless Water Heater (6.5GB-ING) is the second largest capacity model in the Builder Series. CSA approved and rated at an impressive 6.5 GPM with a temperature rise of 45 degrees. This tankless water heater is rated at  170,000 BTU and can produce unlimited hot water for 3-4 applications simultaneously. Eccotemp’s advanced 0.66 GPM low flow ignition technology allows users to enjoy endless hot water without experiencing cold spots.

We recommend the 6.5 GPM Indoor Natural Gas Tankless Water Heater (6.5GB-ING) for large, medium, and small size single family homes, townhomes, condos, cabins, as well as smaller commercial applications and home builders. With our upgraded product control board performance and an all-new gas modulating valve, consumers can experience best in class temperature performance that is budget friendly.

The space saving wall mounted Eccotemp 6.5GB-ING has a 110/120-volt UL listed power cord that powers the internal exhaust fan, anti-Freeze protection and product control board. With its fully automated control system, the Eccotemp 6.5GB-ING pulls less than 0.6 amps during operation, making it ideal for low energy consumption and efficiency.

The Eccotemp 6.5GB-ING has been CSA tested and approved for US & Canadian use at elevations up to 2000 feet. Installation and use of the Eccotemp 6.5GB-ING above 2000 feet may affect overall product efficiency and performance.

IMPORTANT NOTE: Cannot be used for HYDRONIC SYSTEMS, RECIRCULATING, or FLOOR HEATING.

All purchases valued at $75 or above will be shipped with SIGNATURE REQUIRED. If you wish to remove the SIGNATURE REQUIRED please contact Customer Service. Please Note: By opting out of SIGNATURE REQUIRED, you release Eccotemp from all liability of lost or stolen packages. Call 1-866-356-1992 or chat with us to speak with a customer service agent.

Features                    

• Rated for 3-4 applications means enjoying on-demand hot showers for up to 3 bathrooms simultaneously
• Rated at 6.5 GPM (gallons per minute) at 170,000 BTUs with a temperature rise of 45 degrees, this ultra-efficient tankless hot water heater is the second largest capacity model in the Eccotemp Builder Series and ideal for just about every size single-family home, townhome, condo, cabin, apartment, or light commercial use in the US and Canada
• CSA certified for installation in the US and Canada. This tankless water heater meets and exceeds all safety and efficiency requirements according to the DOE
• Advanced Generation 3 Computer board with high performance processing and smart adjust technology built in. Our proprietary developed programming meets and exceeds today’s consumer demands
• With advanced incoming and outgoing water temperature sensor technology, you always have total confidence when it comes to safety
• The 6.5GB Builder Series is designed for indoor installation only and requires 3-inch venting. Make installation a breeze using the Eccotemp 3" Horizontal Vent Kit or 3” Vertical Vent Kit (purchased separately).
• 10-Year limited manufacturer warranty (heat element: 10-years, Parts: five years), live chat, appointments for product support, and self-help guides will give you peace of mind that the Eccotemp 6.5GB-ING  will keep you in hot water for years
• What's Included: Eccotemp 6.5 GPM Indoor Natural Gas Tankless Water Heater (6.5GB-ING), mounting hardware, gas appliance shut off valve, and product manual
• The Eccotemp 6.5GB-ING  can be complemented with our patented, one of a kind EZ-Flush Descaling Kit to ensure your tankless water heater is running at maximum efficiency all year long

What our Experts Think

Q&A  

Q: What is this Eccotemp 6.5 GPM indoor unit?
A: It is a high-capacity indoor natural gas tankless water heater designed for whole-home use, delivering continuous on-demand hot water for multiple fixtures at once.

Q: What does 6.5 GPM mean?
A: It means the unit can supply up to 6.5 gallons of hot water per minute, supporting about 3–4 simultaneous uses like showers, sinks, and appliances.

Q: What is its heating power?
A: It is rated at up to 170,000 BTU, allowing strong and stable heating performance for medium to large homes.

Q: What makes it suitable for indoor installation?
A: It includes a built-in exhaust fan, electronic control board, and requires 3-inch venting, designed specifically for safe indoor wall-mounted installation.

Q: What does “Scratch & Dent” mean?
A: It means the unit is fully tested and functionally working, but may have cosmetic imperfections, missing minor accessories, or refurbished parts, sold at a reduced price.

Q: Is it efficient for home use?
A: Yes. It uses a modulating gas valve and low-flow ignition technology, helping maintain stable temperatures while reducing energy waste.

Q: What type of homes is it best for?
A: It is suitable for single-family homes, townhouses, condos, cabins, and light commercial use needing reliable multi-point hot water supply.

                 
Maintenance Tips                

• Descale every 6–12 months using a flush kit to prevent mineral buildup in the heat exchanger and maintain flow efficiency
• Clean inlet water filter regularly to avoid low flow, ignition issues, and error codes
• Inspect 3" indoor vent system for blockages, loose joints, or dust buildup to ensure safe exhaust airflow
• Check gas line & water connections for leaks, corrosion, or pressure inconsistencies before peak usage seasons
• Keep temperature around 120°F to reduce scaling and improve energy efficiency
• Test safety features annually (flame sensor, anti-freeze system, error code response) for reliable operation
• Flush before winter or heavy-use periods if water hardness is high (hard water accelerates scaling)
• Ensure proper flow rate (≥0.5 GPM activation threshold) by cleaning shower heads and aerators if performance drops
• Schedule yearly professional inspection for burner, gas pressure calibration, and internal safety components