Lennox ML180UH070XE36B 80% AFUE 66,000 BTU 17.5" Gas Furnace

The Lennox ML180UH070XE36B is a Merit Series single-stage gas furnace rated 66,000 BTU input and 53,000 BTU output at 80% AFUE. It comes in a 17.5-inch B cabinet, installs upflow or horizontal, and has a constant torque blower sized for 1.5 to 3 tons of add-on cooling.

Key specs

• Heating: 66,000 BTU input, 53,000 BTU output, 80% AFUE, single-stage
• Cabinet: B size, 17.5 inches wide, upflow or horizontal (left or right)
• Blower: 1/2 hp constant torque motor, 395 to 1,415 cfm, for 1.5 to 3 tons of cooling
• Temperature rise: 40 to 70°F

Reading the model number

ML is Lennox's Merit line, 1 means single-stage, 80 is the AFUE, and UH is upflow/horizontal. 070 is the 66,000 BTU input, X means it meets California's 40 ng/J NOx standard, E is the high efficiency constant torque blower motor, 36 is the nominal add-on cooling size, and B is the 17.5-inch cabinet.

What it pairs with

Coils with the same letter physically match the furnace, so you want a Lennox coil with B in its size code, such as a CK40CT, CK40HT, or CK40UT.

The AHRI Directory lists this furnace in certified systems with CK40CT, CK40HT, and CK40UT coils and Lennox EL15KC1, EL16KC1, EL18KCV, EL22KCV, ML13KC1, ML14KC1, and ML17KC2 air conditioners, plus EL16KP1, EL18KSLV, EL19KPV, EL21KLV, and ML14KP1 heat pumps. Your efficiency rating depends on the exact outdoor unit, coil, and furnace together.

Sizing and fit

Size the furnace from a Manual J load calculation. Filters and filter mounting aren't included, so plan for a filter rack.

Even with the X low NOx code, Lennox says this furnace series can't go in the South Coast, San Joaquin Valley, and Bay Area air districts. It isn't certified for mobile homes, RVs, or outdoor installs.

Warranty and registration

HVAC USA is an authorized Lennox reseller, and everything we sell is new factory equipment. Your full Lennox warranty applies when a licensed, manufacturer-certified contractor installs your system and registers it within 60 days.

Compare related Lennox furnaces

Compare this furnace with other Lennox 80% AFUE furnaces, Lennox Merit furnaces, Lennox single-stage furnaces and Lennox 66,000 BTU furnaces. You can also browse all Lennox gas furnaces. Adding cooling? Pick a matching Lennox evaporator coil for the cabinet width.

Shipping and help

This item ships free from our Kansas City warehouse to the lower 48 states and D.C., and so does the rest of your order, except to Washington, Oregon, and Idaho, where you pay the shipping rate shown at checkout. For Alaska, Hawaii, Puerto Rico, other U.S. territories, or an APO or FPO address, call or text us for a quote. Call (913) 364-0070, Monday to Friday, 9am to 5pm CST, and we'll help you confirm sizing and an AHRI-matched pairing before you order.