HVAC Refrigeration Guide — troubleshooting
Heatcraft Bohn Larkin Unit Cooler Troubleshooting
HVACR techs: learn how to read Heatcraft IntelliGen alarm codes (AL01, AL06, ER25, ER26) before swapping parts. This guide covers the most common unit cooler faults — high box temp, door open alarms, connection-lost errors, and evaporator fan failure — with confirmed OEM part numbers for the two failures we see most: contactor failure (2259996) and evaporator fan motor failure (25322406).
- Tags: 2259996, 25308301S, 25312601S, 25322406, AL01, AL06, alarm codes, Bohn, Chandler, contactor, ER25, ER26, evaporator fan, Heatcraft, high box temp, HVACR, IntelliGen, Larkin, not cooling, R026215300, refrigeration, troubleshooting, unit cooler, walk-in cooler
Johnson Controls Actuator Field Guide
Johnson Controls actuators, zone valves, and sensors are the backbone of commercial HVAC controls. This field guide covers VA/VG series failure patterns, wiring gotchas, and the parts professional technicians stock for fast turnaround.
- Tags: actuators, building automation, commercial HVAC, control valves, diagnostics, HVAC, Johnson Controls, pressure transducers, temperature sensors, troubleshooting, VA series, VAV, VG series, zone valves
Lochinvar AO Smith Field Guide
Lochinvar commercial water heater troubleshooting: why burner door switches trip, what causes burner soot and flame failure, and when to replace the relief valve.
- Tags: 100111113, 100274785, 100292715, AO Smith, burner assembly, commercial boiler, commercial water heater, door temperature switch, field guide, FVIR, HVAC parts, Lochinvar, lockout, OEM parts, pressure relief valve, soot, troubleshooting
Run Capacitor Field Guide
Run capacitors fail silently and take compressors and fan motors with them. This field guide covers failure mechanisms, accurate testing procedures, MFD tolerance rules, and stocking strategy for HVACR technicians.
- Tags: 370V, 440V, capacitor replacement, capacitor testing, compressor, condenser fan motor, dual run capacitor, field guide, HVAC, HVACR, MFD, motor capacitor, run capacitor, troubleshooting, truck stock
Lennox Parts Field Guide
Lennox HVAC parts field guide for professional technicians — capacitors, contactor failures, condenser fan motors, control boards, and OEM part numbers. Stock smarter, diagnose faster.
- Tags: Capacitor, Condenser Fan Motor, Contactor, Control Board, Field Guide, HVAC, iComfort, Lennox, OEM Parts, Pressure Switch, Summer HVAC, Troubleshooting, XC16, XC20, XC21