Lennox CBA25UH-042 21.5" Width 42,000 BTU Air Handler

The Lennox CBA25UH-042 is a 3.5 ton Merit Series air handler for R-410A systems, with a multi-speed PSC blower and an R-410A check/expansion valve installed at the factory. It comes in a 21.5-inch wide cabinet that ships ready for upflow or horizontal installs. Lennox sells CBA25UH air handlers in the US for repair and replacement only, not for new system installs.

Key specs

• Capacity: 3.5 tons (42,000 BTU)
• Blower: 3/4 hp PSC motor, 568 to 1,656 cfm
• Connections: 3/8-inch liquid and 7/8-inch suction, sweat, plus two 3/4-inch FPT drains
• Filter: 18 x 20 x 1 inch
• Shipping weight: 169 lb
• Coil: Lennox Quantum coil with aluminum tubing and ripple-edged aluminum fins

Reading the model number

CB is an air handler, A is the aluminum coil for R-410A, and 25 is the series. UH is upflow/horizontal and 042 is 3.5 tons. Lennox's full model number adds 230 for 208/230V single-phase and a minor revision number. You may also see it written as CBA25UH-042-230.

What it pairs with

It has to connect to an R-410A outdoor unit. The air conditioners and heat pumps we sell use R-454B, so this air handler is for keeping an existing R-410A system running.

For electric heat, Lennox lists ECB45 heaters from 4 to 15 kW for this size: 4, 5, 7.5, and 10 kW with a terminal block or a circuit breaker; 12.5 and 15 kW with a circuit breaker.

Sizing and fit

Downflow needs Lennox's Y9659 downflow kit, and horizontal left-hand discharge needs the horizontal drain pan moved. Match the air handler to your outdoor unit's tonnage.

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.

Shipping and help

It ships from our Kansas City warehouse to the lower 48 states and D.C. It ships free when your cart also has an item that ships free, except to Washington, Oregon, and Idaho. 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.