What is a hydro-furnace, and how is it different from a regular furnace?

It is a condensing appliance that heats water and delivers warm air through a coil, combining space heating and domestic hot water in one unit. That saves floor space and one gas connection versus separate furnace and water heater.

Is 97 AFUE worth the extra cost?

At 97 AFUE it converts nearly all gas input to heat, so it uses less gas than an 80 AFUE furnace. The savings depend on your climate and gas rate, and the higher install cost takes years to pay back.

What size do I need for my house?

Input ranges from 14,000 to 100,000 BTU/h across the line, and the NPF700 060U3BH is a 60,000 BTU model. A load calculation (Manual J) decides the right size; oversizing causes short cycling.

Can it vent through an existing chimney?

No. It is a condensing unit and needs PVC or CPVC venting, up to 70 ft in 2-inch or 140 ft in 3-inch pipe. It cannot share a masonry chimney with other appliances.

Does it work with my thermostat?

It is compatible with single-stage or two-stage thermostats. A two-stage thermostat lets the variable-speed blower and modulation run at lower output for steadier heat.

What comes in the box?

The unit ships with an LP conversion kit and a high-altitude kit good up to 10,100 ft. Vent pipe, condensate pump and thermostat are not included.

Where is the Navien NPF Hydro-Furnace cheapest?

At hvac place, for $2,667.56, as of our latest check.

Where can I buy the Navien NPF Hydro-Furnace?

2 stores we checked sell it, including eBay, hvac place.

Navien NPF Hydro-Furnace

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$2,667.56at hvac placeObserved at 8:44 AM

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Our take on the Navien NPF Hydro-Furnace

The Navien NPF is a condensing hydro-furnace that heats water and air in one unit, rated at 97 AFUE with a variable-speed ECM blower and 14,000–100,000 BTU/h input. It runs on 120V with a 20-amp circuit and vents up to 70 ft in 2-inch pipe or 140 ft in 3-inch. It meets SCAQMD Rule 1111 ultra-low NOx limits and ships with LP and high-altitude kits. The best new price is $2,667.56 at hvac place as of November 7, 2026, the only new listing found.