HVAC Refrigeration Guide

TXV Troubleshooting in the Field

Jul 15, 2026

A failing TXV rarely throws a fault code — it shows up as frost on the suction line, erratic superheat, or a system that won't hold temperature no matter how much refrigerant gets added. This guide walks through the five field symptoms that point to the valve (not the charge), how to confirm a bad TXV before replacing it, and how to match the right replacement by refrigerant type and equalization style — with notes on the Danfoss 068U1839, Copeland Alco 091050, and Amana-Goodman OEM valves.

Tags: Amana-Goodman, Copeland, Danfoss, Expansion Valve, Field Service, HVAC Troubleshooting, HVACR Parts, R-134a, R-22, R-410A, Refrigerant, Superheat, TXV

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

Blower Motor Failing? How to Diagnose and Pick the Right Replacement

Jul 08, 2026

Blower motor humming, cycling on high-limit, or won't start? Learn the failure signs, how to tell PSC from direct-drive from burner motors, and which OEM replacement fits your application.

Tags: Amana, blower motor, combustion air, direct-drive motor, furnace repair, Goodman, hearth heater, high-limit switch, HVAC diagnostics, Midco, motor replacement, power burner, PSC motor, run capacitor, Williams

Johnson Controls Actuator Field Guide

Jul 01, 2026

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

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