Dual Venturi system creates better combustion control, turndown ratio and easy field gas conversions.
2" venting up to 65' (including schedule 40 PVC).Vent Installation Detector (VID) for added safety.
Patented stainless steel fire tube heat exchanger Navien’s innovative heat exchanger design is ASME‑Certified,“H” Stamped, and reduces high-stress point weld failures common on other combi-boilers.
Advanced user interface with Setup Wizard is made easy with backlit panel, click-wheel control and intuitive text.
Low gas pressure operation. Negative pressure regulating gas valveensures maximum performance all the way down to 3.5" of water column on natural gas and 8" of water column on propane gas.
Dual Venturi system creates better combustion control, turndown ratio and easy field gas conversions.
1/2" gas pipe capability up to 24' (subject to local codes). Cuts installation time, no need to install new gas lines for retrofit applications.
Patented stainless steel fire tube heat exchanger Navien’s innovative heat exchanger design is ASME‑Certified,“H” Stamped, and reduces high-stress point weld failures common on other combi-boilers.
NHB integrated control provides industry-leading options and features including adjustable heat capacity, temp boost for outdoor reset control, adjustable anti-cycle timer and freeze protection.
The condensing technology of the dual stainless steel heat exchangers saves energy, reduces greenhouse gasses.
1/2" gas pipe capability up to 24' (subject to local codes). Cuts installation time, no need to install new gas lines for retrofit applications.
The sophisticated gas flow control system provides a high turndown ratio which reduces energy waste and excessive boiler cycling.
NHB integrated control provides industry-leading options and features including adjustable heat capacity, temp boost for outdoor reset control, adjustable anti-cycle timer and freeze protection
The condensing technology of the dual stainless steel heat exchangers saves energy, reduces greenhouse gasses
2" venting up to 65'; 3” up to 150’ (including schedule 40 PVC)
The sophisticated gas flow control system provides a high turndown ratio which reduces energy waste and excessive boiler cycling
Buy new Boiler Viessmann Heat Only in just a few steps
Make an order
Contact us to buy a new boiler. Our team will guide you every step of the way and help you choose the right model.
Arrival of a technician
Once your order is confirmed, we will promptly visit your location and conduct a thorough inspection, ensuring all necessary details are clear.
Delivery and installation work
We will deliver the boiler to you. Our team will handle the installation with efficiency and professionalism, ensuring a seamless setup.
Get a warranty
We offer a warranty that covers different parts and services. Even after the warranty expires, you can rely on our post-warranty services.
Why should you buy a Boiler Heat Only Navien from us?
9.7/10
215 reviews
4.8/5
reviews
Aunice Torres
Nov 01, 2025
Superior HVAC Heating and AirConditioningrepaired my furnace quickly and accurately. Friendly and skilled technician named Sean who made sure everything was perfect. Great company to call for HVAC repairs and maintenance.
Sophia Gineto
Dec 09, 2025
Ryan from Superior HVAC Service performed a full duct cleaning and balanced airflow through each vent. The house feels evenly heated for the first time this winter.
fatma mahmoud
Jan 31, 2025
My furnace wasn’t keeping the house warm, so I reached out to Superior HVAC Service. Sean showed up on time, diagnosed the problem quickly, and had it fixed before I knew it. He also checked my water heater to ensure everything was working properly. Excellent service—highly recommend!
Arik Vilensky
Jan 27, 2025
Brian did an awesome job fixing our AC unit. He was quick, knew exactly what was wrong, and got it running perfectly again. Super happy with the service!
eliamae entigro
Jan 27, 2025
Thank you Hunter of Superior Plumbing and Heating for making repairs on my damaged water heater.
Madison Fleck
Oct 29, 2025
Evan from Superior HVAC Service ran a combustion analysis on our gas furnace. He adjusted the air-to-fuel ratio and optimized performance. It runs better than it has in years.
Nicolas Gumienik
Dec 24, 2025
Liam replaced me 20 year old furnace. The crew came within 6 hours and were very neat and tidy when installing !
We will deliver Navien Heat Only Boilers to any of these cities
Nov 01, 2025
Ajax