HVAC Refrigeration Guide — HVAC Parts

Lochinvar AO Smith Field Guide

Jun 28, 2026

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

Friedrich Parts Field Guide

Jun 10, 2026

Friedrich PTAC and commercial AC parts fail in predictable patterns across high-density installations. This field guide covers control board failures, fan motor specs, and the diagnostic sequences professional technicians use to turn multi-unit service calls fast.

Tags: capacitors, commercial HVAC, control boards, diagnostics, fan motors, Friedrich, Friedrich parts, heat pump, hotel HVAC, HVAC parts, OEM parts, PTAC, PTAC maintenance, PTAC repair, thermistors

Daikin-McQuay Parts Field Guide

May 17, 2026

A field guide to the most common Daikin-McQuay failures — control boards, condenser fan blades, freeze stats, and NTC sensors — with diagnostic tables, misdiagnosis traps, and stocking recommendations for professional HVACR technicians.

Tags: Commercial HVAC, Condenser Fan Blades, Control Boards, Daikin-McQuay, Freeze Stats, HVAC Parts, HVACR Technicians, NTC Sensors, Rooftop Units, Troubleshooting

Bard HVAC Parts Field Guide

May 10, 2026

Bard wall-mount packaged units fail in recognizable patterns. This field guide covers the most common failure modes — condenser fan motors, blower motors, and control boards — with diagnostic sequences, field observations, and the OEM parts techs should have stocked before summer cooling season hits.

Tags: Bard HVAC, Blower Motor, Commercial HVAC, Condenser Fan Motor, Control Board, HVAC Diagnostics, HVAC Field Guide, HVAC Parts, Motor Capacitor, OEM Parts, Summer Startup, Wall-Mount Units