HVAC Refrigeration Guide — furnace troubleshooting

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

Heil Quaker Furnace Flashing a Code? Here's What Every LED Pattern Actually Means

Jul 12, 2026

Heil Quaker/ICP furnace flashing a fault code? Decode the LED sequence, find the failed component, and get OEM parts that fix it right the first time.

Tags: Comfortmaker, control board, furnace repair, furnace troubleshooting, Heil Quaker ICP, HVAC diagnostics, ICP parts, inducer motor, LED flash codes, limit switch, no heat, OEM parts, pressure switch, Tempstar

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