Which furnace heats a bigger house?

The 88,000 BTU furnace. It puts out 85,000 BTU at 97% AFUE, while the listed Navien NPF700 060U3BH is 60,000 BTU input. The Navien NPF line does reach 100,000 BTU input in other models.

Is the Navien worth the extra $1,438?

Only if you need what it adds: SCAQMD low-NOx compliance, an included LP kit, the high-altitude kit, and a narrower cabinet. For raw heating capacity per dollar, the 88,000 BTU furnace wins.

Do either include a propane conversion kit?

The Navien includes an LP conversion kit standard. The 88,000 BTU furnace does not; you need kit 68W77, sold separately.

Which is easier to fit in a tight space?

The Navien, at 17.5 inches wide versus 21 inches for the 88,000 BTU furnace. The Navien is taller at 34.5 inches.

Neither listing states a service life. Both are condensing 97% AFUE units with ECM blowers, so life depends mostly on installation quality and annual maintenance.

Can I use a two-stage thermostat with the Navien?

Yes. Navien lists compatibility with single or two-stage thermostats. The 88,000 BTU furnace uses non-communicating controls.

88,000 BTU Modulating Gas Furnace 97% AFUE vs Navien NPF Hydro-Furnace

Buy the 88,000 BTU modulating furnace if you want the most heat for the money: it delivers 85,000 BTU of output at 97% AFUE for $1,229.00 at Surplus City Liquidators as of November 7, 2026. Buy the Navien NPF Hydro-Furnace if you need a compact, low-NOx unit with an included LP kit and a wide modulation range, at $2,667.56 at hvac place as of November 7, 2026. The Navien costs about $1,438 more and its listed 60,000 BTU input version puts out far less heat.

Today the 88,000 BTU Modulating Gas Furnace 97% AFUE costs $1,438.56 less at its best price.

Ask our shopping agent

It checks today's price at every store, compares the alternatives and answers in about a minute.