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Navien

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

4.8 out of 5 · 6 reviews

$5,525.00

SKU NNFB399C · Taxes calculated at checkout

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Delivery
Ships in 1 business day (Mon–Fri), arrives in 1–3 business days (Mon–Fri). Order before 11:00 PM CST (UTC −6) to ship the next business day.
Returns
90 days from delivery, defective or not. No restocking fee. Approved refunds land within 7 business days.
Warranty
Three-Year Limited Warranty against manufacturing defects under normal use conditions — or the manufacturer's term where that is longer.

Questions before you order? Call +1 575 271 0768

Product details

Rated at 399,000 BTU, this sits at the high end of the NFB-C commercial range. The stainless steel fire tube heat exchanger is patented and built to keep stress off the welds, while a dual venturi system tightens combustion control and extends the turndown range. Maximum operating pressure is 160 PSI.

A 7-inch color display handles setup, diagnostics, and day-to-day operation, and BAS communication is supported for buildings with central controls. Top and bottom pipe connections suit either a floor-standing or wall-hung installation, and an orifice and conversion kit for liquid propane come in the box. Warranty terms are ten years on the heat exchanger, three years on parts, one year on labor.

Customer reviews

What people say about buying from us

4.8 out of 5 from 6 store reviews. These cover the buying experience across our catalog, not this product alone.

  • Arrived early and packed properly

    Ordered on a Thursday and it was on a pallet outside my garage Monday morning. Every board was numbered and the hardware came in labelled bags, so we did not have to guess at anything. Two of us had it standing by Sunday afternoon.

    Marcus T.· Round Rock, TXVerified order

  • Lumber quality is genuinely good

    I have built two of these from other brands and returned one for warped boards. Not a single warped piece in this kit. The kids have been on it every day since we finished it.

    Dana R.· Columbus, OHVerified order

  • Correct weight, factory sealed, clean invoice

    Ordered Thursday, on the truck Friday. Cylinder was sealed and the weight was exactly right. The invoice had everything my bookkeeper needed, which is more than I can say for the supplier I was using before.

    Victor A.· Hialeah, FLVerified order

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