HVAC Refrigeration Guide — hvacr

Heatcraft Bohn Larkin Unit Cooler Troubleshooting

Jul 19, 2026

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

Fasco Motors Field Guide

Jun 03, 2026

Fasco motors power blowers and draft inducers across dozens of HVAC brands. This field guide covers failure patterns, replacement spec matching, rotation and mounting traps, and stocking strategy for HVACR technicians.

Tags: blower motor, commercial HVAC, draft inducer, Fasco, field service, HVAC diagnostics, HVAC motors, HVACR, inducer motor, Lennox, motor replacement, Nordyne, OEM parts, PSC motor, residential HVAC, run capacitor, York

HVAC Contactor Failures

May 31, 2026

HVAC contactor failures are one of the most misdiagnosed calls in commercial HVAC. This field guide covers burn patterns, coil voltage matching, contact pitting diagnosis, and what to stock before peak season hits.

Tags: coil voltage, commercial HVAC, compressor, contact pitting, contactor, contactor failure, field service, HVAC, HVAC diagnostics, HVAC repair, HVACR, OEM parts, residential HVAC, welded contacts

Run Capacitor Field Guide

May 27, 2026

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

The Pressure Switch Field Guide

May 03, 2026

Pressure switches are the most misdiagnosed component in HVACR service calls. This field guide covers how pressure switches work, the four real failure modes (diaphragm fatigue, condensate ingestion, hose deterioration, and contact failure), the correct diagnostic sequence, and brand-specific patterns for Cleveland Controls, Dwyer, Nordyne, and Daikin-McQuay equipment.

Tags: cleveland-controls, commercial-refrigeration, condensate, control-board, daikin-mcquay, diaphragm-failure, dwyer, field-guide, furnace-troubleshooting, hvac-diagnosis, hvacr, inducer-motor, nordyne, pressure-switch, technician-resources