Navien Condensing Combi Gas Boiler

The Navien Condensing Combination boilers are perfect for people who need both hot water and a space heating application. It heats water in your home when needed, making it environmentally friendly and cost efficient.

NCB Models Max Input: up to 120k BTU's Heating + 199k BTU's Domestic Hot Water plus 4.5 GPM hot water flowrate


Hydronic Heating Benefits

Comfort, Silence and Economical Heating

The radiant heat allows for heating from the floors to the ceiling for overall comfort.


Since no blowers are needed to transfer heat, your home can be warmed up nice and quietly.


Even after the boiler is turned off, the radiant heat from the floors continues to transfer throughout your home for hours.

Energy Efficient

The Navien NCB is rated at up to 98 EF, or 98% efficient for top energy efficiency in a gas boiler.

Smart Remote Control System

Included With Combi-Boiler

LCD Display

Easy to Use

24 Hour Time Scheduling

combi boiler screen

Dual Stainless Steel Heat Exchangers

Extended Life & Highest Flow Rate

Old boilers typically used copper heat exchangers. Since your heat exchanger is doing all the work, it needs a stronger material to handle the load for years to come. Stainless steel is the optimal material to resist corrosion.

The unique stainless steel flat plate heat exchanger creates the highest flow rate for domestic hot water of any combi-boiler in the industry, 4.5 GPM @ 77 degrees.

Leak Detector Accessory

Your Safety in Mind

The leak detector feature detects the first sign of water to prevent damage to your water heater or personal belongings.

Strong Anti-Freeze Feature

To Prevent Frozen Pipes

Prozen pipes in the winter can be costly and leave you cold with no heat. The Combi’s built-in Control system was engineered specifically to withstand colder conditions.

Other Features of the Navien Combi-Boiler

Environmentally Friendly Low NOx Emissions
Qualified for Utility Rebates
Can run on natural gas or easily convert to propane
80% smaller size than a traditional floor standing boiler or tank water heater, truly space saving
Excellent Warranties, Ask for Details

Learn More

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Your Own Home Energy Specialist

To Help You Make an Informed Decision

Every home is different and one heating system may not be ideal for another. Your knowledgeable energy specialist will provide you with the best heating choices and honest advice on the pros and cons of each to help you make an informed decision.

One Contact from Beginning to End

It doesn’t stop there. Once you’ve chosen the boiler that fits your life, they will be there to answer any of your questions throughout the entire process. You have a single contact to go to before, during and even after your boiler is installed.

100% Satisfaction Guarantee

Yes, We Trust Our Team & Products THAT Much

We back every project we install with our 100% Satisfaction Guarantee. If you are not completely satisfied with our products or services, we will simply remove our equipment and refund your money.*

The Best Installers in the Industry

Continuous Training

Each boiler technician receives continuous year round training to ensure everyone is up to date and fresh on best installation practices and procedures.

No Shortcuts
Licensed, Bonded & Drug Tested

All of our boiler technicians undergo stringent background checks and drug screens to ensure your safety.

No Subcontractors

Keeping it in the House

We do not use subcontractors to install any of our boilers. Your brand new boiler will be professionally installed by Washington Energy Services employees only.

NATE Certified

Details Matter

Our technicians are NATE Certified. When choosing a company to perform the install, be sure to ask for NATE accreditation as not all companies obtain proper certification. NATE exams reflect a consensus opinion of what technicians need to know to effectively service and install today’s sophisticated HVAC systems. Technicians should be NATE certified in the same way a doctor shouldn’t be practicing without a license. To protect consumers, NATE (North American Technician Excellence) formed as a 3rd party, non-profit, certification program for the HVAC industry. The NATE technical committee developed strict guidelines and tests that HVAC companies must pass in order to become NATE certified.

BBB A+ Rating

A Badge you Can Trust

We’re honored to get BBB Accreditation as not every company is eligible. BBB is the resource to turn to for objective, unbiased information on businesses. Businesses must meet their high standards and we continue to live up to their Standard of Trust by emphasizing fair & honest practices for our customers.

What are some gas boiler replacement warning signs?

Your gas boiler may be beyond repair if:

20 years+ old

If your boiler is over 20 years old, it is running on borrowed time and not very efficiently at that.


Hissing is associated with iron or sludge caught up in the system causing it to heat up and shut down. This may be a simple repair, but if left unattended for long enough, it could mean the end for your boiler.

Leaky Water

Leaky water may just be a service or repair but like “Noises” you should get this checked out before it’s too late.

What are the advantages of radiant heating?

Consistent comfortable heat

Radiant heating, aka hydronic heating, provides a more consistent comfort than a forced air system. Hidden radiant systems use piping inside of floors, ceilings, and walls. The combi boiler allows you to heat your water and your whole home at the same time.

In a forced air heated house, you might have a large variation between the temperature at the floor and up higher in the room. Houses heated with radiant systems tend to have uniform temperatures throughout each room. No wonder these systems are so popular in Seattle.

Other Boilers

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