HVAC · planned

Lennox

BACnetModbusREST

Lennox is a major North American HVAC manufacturer focused on residential and light-commercial systems including the iComfort thermostat platform. HVAC API support for Lennox is planned and currently scoped against the Lennox S30 cloud API and standard BACnet/Modbus gateways.

Device families

iComfort Thermostats
2 endpoints
Rooftop Units
1 endpoint

Endpoints & snippets

Fault codes & error codes

9 codes documented for Lennox. Confirm against your model's service manual — some codes vary between product lines (VRV vs. Sky Air vs. residential split, etc.).

9

Code	Category	Meaning	Suggested action	Severity	Help
223	Outdoor unit	High-pressure switch tripAsk AI to troubleshoot →	Check condenser coil cleanliness and fan operation; verify refrigerant charge.	critical	Ask AI →
224	Outdoor unit	Low-pressure switch tripAsk AI to troubleshoot →	Check refrigerant charge and filter-drier restriction.	critical	Ask AI →
411	Furnace / Air handler	Limit circuit open — high-temperature or rollout switch trippedAsk AI to troubleshoot →	Check air filter, blower operation, and heat-exchanger for restriction or cracking.	critical	Ask AI →
412	Furnace / Air handler	Flame rollout switch openAsk AI to troubleshoot →	Inspect heat exchanger for cracking; verify flue is not blocked before reset.	critical	Ask AI →
431	Furnace / Air handler	Inducer or pressure-switch fault (draft proving failure)Ask AI to troubleshoot →	Check inducer motor, pressure-prover tubing for cracks or blockage, and switch continuity.	critical	Ask AI →
433	Furnace / Air handler	Ignition lockout — flame not established after retriesAsk AI to troubleshoot →	Verify gas pressure and supply, spark ignitor, and flame-sensor microamp signal.	critical	Ask AI →
E1	Communicating system	Communication error between thermostat and air handler or furnaceAsk AI to troubleshoot →	Check communicating wiring (4-wire bus) between thermostat, furnace, and air handler; verify no short circuits.	critical	Ask AI →
E2	Communicating system	Communication error between thermostat and outdoor unitAsk AI to troubleshoot →	Check communicating wiring to the outdoor unit; confirm correct unit addressing.	critical	Ask AI →
E3	Communicating system	Duplicate unit address detected on communicating busAsk AI to troubleshoot →	Re-address the conflicting communicating accessory per iComfort setup procedure.	warning	Ask AI →

Lennox

Device families

Endpoints & snippets

Fault codes & error codes

External resources