Navien™ NFB-399C 399,000 BTU Condensing Fire Tube Boiler

Navien™ NFB-399C 399,000 BTU Condensing Fire Tube Boiler – 2

Navien™ NFB-399C 399,000 BTU Condensing Fire Tube Boiler – 3

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Navien

Navien™ NFB-399C 399,000 BTU Condensing Fire Tube Boiler

Name: Navien™ NFB-399C 399,000 BTU Condensing Fire Tube Boiler
Brand: Navien
SKU: NNFB399C
Price: 5525 USD
Availability: InStock
Rating: 4.5 (4 reviews)

4 reviews

$5,525.00

As a global leading boiler maker, Navien™ proudly delivers leadership, dependability, design, green technology, social responsibility, and customer service to over 30 countries worldwide. This assures world-class quality and comfort in every home and business.

Patented stainless steel fire tube heat exchanger reduces high-stress point weld failures common on other boilers
Robotic and automated manufacturing technology for unmatched quality control
Dual Venturi system creates better combustion control and turndown ratio
Conversion kit included and orifice for easy field gas convertibility from natural gas to liquid propane
160 PSI maximum operating pressure

In stock · Delivered in 2–4 business days

Delivery Estimated 5 Nov – 9 Nov · Shipping policy
Returns90-day returns · Refund policy
Secure paymentCard payments processed by Stripe

SKU:: NNFB399C
Category:: Water Heaters & Boilers
Brand:: Navien

Question about this product? Ask us before you buy

Navien’s™ high efficiency fire tube condensing technology makes the NFB-C hard to beat and the easy choice for today’s commercial boiler applications.

Features

Patented stainless steel fire tube heat exchanger reduces high-stress point weld failures common on other boilers
Robotic and automated manufacturing technology for unmatched quality control
Dual Venturi system creates better combustion control and turndown ratio
Conversion kit included and orifice for easy field gas convertibility from natural gas to liquid propane
160 PSI maximum operating pressure
Advanced controls with intuitive 7” color display with intuitive navigation for setup, troubleshooting, and operation
BAS communication capability
Easy top and bottom pipe connections for floor or wall-hung installations

Warranty

This commercial boiler comes with a 10-year heat exchanger, 3-year parts, and 1-year labor limited warranty.

All trademarks are the property of their respective owners.

✓

100% Verified Purchases

Confirmed freight delivery orders

Inspected Freight Delivery

Delivered with liftgate offloading

4.5 / 5.0 Customer Score

Based on 4 customer reviews

4.5

Based on 4 verified purchases

✔ 98% of customers recommend this equipment

5 stars

50%

4 stars

50%

3 stars

Have a technical question? Ask us

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Gary F. ✓ Verified Buyer

San Antonio, TX · Verified Purchase • Liftgate Delivery

September 19, 2026

✔ Recommends this product

Contractor praised the design and fittings

Our heating engineer had this installed and commissioned in under a day. Digital interface makes adjusting domestic hot water and heating setpoints completely intuitive.

✓ Heavy-Duty Build ✓ Prompt Freight Delivery ✓ Smooth Operation

Response from AKASHOP Commercial Team Official

Hello Gary F., thank you for sharing your experience with AKASHOP! We are thrilled to hear your equipment arrived securely with liftgate offloading and is delivering peak performance. Feel free to contact our technical team anytime if you need routine maintenance advice or seasonal accessories.

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Brandon M. ✓ Verified Buyer

Miami, FL · Verified Purchase • Liftgate Delivery

September 7, 2026

✔ Recommends this product

High quality equipment, well worth the investment

Sturdy construction, premium feel, and great practical features. Will definitely order commercial equipment from AKASHOP again.

✓ Heavy-Duty Build ✓ Prompt Freight Delivery ✓ Smooth Operation

Was this review helpful?

Harry J. ✓ Verified Buyer

Nashville, TN · Verified Purchase • Liftgate Delivery

August 2, 2026

✔ Recommends this product

Very satisfied with the Navien unit

Clean installation, modern aesthetic on the wall, and super dependable continuous operation throughout the winter season.

✓ Heavy-Duty Build ✓ Prompt Freight Delivery ✓ Smooth Operation

Was this review helpful?

Olivia M. ✓ Verified Buyer

Charlotte, NC · Verified Purchase • Liftgate Delivery

July 13, 2026

✔ Recommends this product

Does exactly what it promises with zero hassle

Clear instructions, durable build, and good value. Arrived on schedule with full tracking link.

✓ Heavy-Duty Build ✓ Prompt Freight Delivery ✓ Smooth Operation

Was this review helpful?

Questions & answers

How much is delivery and when will it arrive?

Delivery is free. This order is usually delivered in 2–4 business days (estimated Nov 5 – Nov 9). Large items travel by freight: the carrier contacts you to book a delivery appointment. Shipping policy

Can I return it?

Yes, within 90 days of delivery, with no restocking fee. Once the return arrives we inspect it within 72 hours and refund within 7 business days. Return policy

Is there a warranty?

Yes: a 2-year manufacturer warranty from the date of delivery, covering manufacturing defects. Warranty details

Is assembly included?

Products are delivered as the manufacturer ships them. Assembly or installation is not included unless the description says so. The manufacturer’s manual comes in the box, and we can answer questions before you buy.

How do I pay, and is it secure?

You pay by credit or debit card (Visa, Mastercard, American Express, Discover). Payments are processed by Stripe: your card details never reach our servers.

I have another question about this product

Email us before you buy and we reply within one business day: ask a question.