Ducane
Allied Air (Lennox International) value badge — basic single-stage equipment, a frequent flyer in rental and multi-family replacement.
The family: Lennox, the Allied Air set (Armstrong Air, AirEase, Ducane, Concord), ADP coils and air handlers, and Magic-Pak wall units.
Same family: Lennox, Armstrong Air, AirEase, Concord, ADP (Advanced Distributor Products), Magic-Pak
What they make
Split system A/C (straight cool)
Covered in the simulatorOutdoor condenser plus an indoor furnace-and-coil or air handler — the most common machine in single-family homes and garden-style multi-family.
The whole sim is built on this machine: every wing of the board and the guided no-cool flow apply directly.
Start a guided call →Practice: whole system dead →Practice: outdoor unit dead →Practice: runs but won’t cool →Practice: no air inside →Practice: acting possessed →Practice: blows fuses →Practice: gauges on →Practice: wrong part, wrong size →A2L start-up guide →
Heat pump (split)
Lessons carry overA split system that also heats: one reversing valve decides which coil condenses. Everything a straight-cool split has, plus the O (or, on some brands, B) circuit and defrost.
The HEAT PUMP wing of the board works the reversing valve; the guided flow routes heat pumps to escalation until its playbook ships. The electrical side transfers one-for-one.
Open in the Copilot (reference) →Practice: heat pump →Practice: whole system dead →Practice: outdoor unit dead →Practice: runs but won’t cool →Practice: no air inside →Practice: acting possessed →Practice: blows fuses →Practice: gauges on →Practice: wrong part, wrong size →A2L start-up guide →
Gas furnace
Covered in the simulatorThe indoor half of most split systems outside the Sun Belt: burners and heat exchanger below, the A-coil above, the 24V control system inside.
The control side — door switch, transformer, board, blower, low-voltage fuse — is fully modeled as the sim’s indoor cabinet, and the guided flow applies on cooling complaints. Combustion-side diagnostics are on the roadmap.
Start a guided call →Practice: whole system dead →Practice: no air inside →Practice: acting possessed →Practice: blows fuses →
Air handler / fan coil
Covered in the simulatorThe all-electric indoor cabinet: blower, coil, and controls. In multi-family it hides in closets and mechanical rooms; hydronic fan-coil versions swap the coil’s refrigerant for water.
Modeled as the sim’s indoor unit: control power, blower circuits, condensate float, coil airflow. Hydronic (water-coil) versions add loop diagnosis the sim doesn’t model yet.
Start a guided call →Practice: whole system dead →Practice: no air inside →Practice: runs but won’t cool →Practice: acting possessed →Practice: blows fuses →Practice: gauges on →A2L start-up guide →
Evaporator coil
Covered in the simulatorThe indoor coil itself — cased or uncased, A, N or slab — often replaced separately from everything else, which is where mismatches are born.
Freeze-ups, restrictions, airflow starvation and mismatched-coil audits are all on the board, and the guided flow’s superheat/subcooling paths read straight through it. Match by capacity and metering device, never by badge.
Start a guided call →Practice: gauges on →Practice: runs but won’t cool →Practice: wrong part, wrong size →A2L start-up guide →
Package unit
Lessons carry overThe whole system in one outdoor cabinet — on a pad beside the house or on the roof. Gas/electric, straight cool, or heat pump.
Same parts, one cabinet: contactors, dual-run caps, PSC/ECM motors and the refrigerant circuit fail exactly like the board’s scenarios. The guided flow’s split-system routing doesn’t fit a single cabinet, so it escalates package units by design.
Open in the Copilot (reference) →Practice: runs but won’t cool →Practice: blows fuses →Practice: gauges on →
Tech support
Tech support here is the guided Copilot with your Ducane info already loaded — one question at a time, evidence before parts, and everything you enter rides into the service report.
Opens the guided Copilot with Ducane already on the equipment card.
Reading Ducane model numbers
Lennox writes series-dash-size: 14ACX-036 reads 14 SEER / ACX line / 036 = 3 tons; XC16-048 is the Elite 4-ton. Allied Air brands (Armstrong, AirEase, Ducane, Concord) use 4SCU/4SHP-style prefixes with the same trailing size. Furnaces (ML195, EL296V, SLP98V) put AFUE in the name and heating input elsewhere — don’t read furnace digits as tonnage. Magic-Pak all-in-ones put cooling capacity in the TRAILING block (…-241/-301/-361 = 2 / 2.5 / 3 tons); the digit right after MHP/MGE is the series generation and the middle token is the efficiency class — neither is a size.
14ACX-036-230— Lennox Merit split A/C, 14 SEER, 3 tons (036).4SCU16LS148P— Allied Air split A/C, 16 SEER, 4 tons (48).
Thirty years of these units
1990s–2000s: 10ACB/12HPB R-22 era. 2010s: 13ACX/14ACX/XC lines on R-410A. 2020s: EL/SL variable-capacity and A2L transitions.
Lennox residential packages (LRP14/LRP16) put tonnage right in the model: LRP14AC36 = 3 tons.
Dating a unit from the serial
Lennox serials lead with plant digits then two year digits (e.g., 5807C… → 2007). Allied brands differ — check the family table. Serial 5807C12345 → 2007 build.
Common rule — spot-check against the manufacturer’s table
Need the wiring? The practice board’s ladder diagram is live and interactive — the same circuit these units share, with a meter on it. Open the board →