HVAC Refrigeration Guide — HVAC repair

Armstrong Furnace LED Flash Codes: Diagnose Before You Replace

Aug 02, 2026

Armstrong furnace flashing 2, 3, or 7? Count the LED before you open anything. This guide maps every flash code to its likely cause — pressure switch, inducer motor, or ignition electrode — and shows you how to confirm the right part before ordering.

Tags: 27X92, ALPKT516-4, Armstrong Furnace, Flash Codes, Furnace Fault Codes, Furnace Troubleshooting, Heat Strip, HVAC Repair, Ignition Lockout, Inducer Motor, LP Conversion, Pressure Switch, R100684-04, R101523-01, R45688-001

Beckett Oil Burner Parts Field Guide

Jun 24, 2026

Beckett oil burner igniters, electrodes, nozzles, and fuel pumps fail in patterns that experienced technicians recognize immediately. This field guide covers Beckett AF, AFG, and AFII burner components — with diagnostic sequences, OEM part number references, and the misdiagnosis traps that generate the most unnecessary callbacks.

Tags: Beckett, Beckett AF, Beckett AFG, Beckett AFII, Beckett NX, Beckett oil burner, Beckett parts, cad cell, carbon tracking, combustion analysis, combustion head, commercial oil burner, electrode assembly, electrode gap, electrodes, field guide, fuel pump, gap drift, heat soak, heating season, HVAC, HVAC repair, igniters, lockout, NL42XN, NL50YB, no ignition, nozzles, OEM parts, oil burner, oil burner diagnostics, oil-fired equipment, primary control, residential oil burner, solid-state igniter

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