Menu
Cart 0

HVAC Refrigeration Guide — Pressure Switch

AAON RTU No Heat? Diagnose Electric Heat, Inducer & Controller

AAON RTU No Heat? Diagnose Electric Heat, Inducer & Controller

Most AAON RTU no-heat service calls trace back to one of three failure points: an open electric heating element, a worn draft inducer that can't close the pressure switch, or a controller that won't communicate. This guide walks through how to confirm which failure you're actually dealing with — before you order a part.

Read more →

Danfoss Compressor & Control Failures: Diagnose Before You Replace

Danfoss Compressor & Control Failures: Diagnose Before You Replace

Danfoss compressor and control failures follow predictable patterns — a scroll that won't start, a reciprocating unit losing capacity, a pressure switch nuisance-tripping, or a TXV that won't hold superheat. This guide breaks down each failure category with diagnostic steps and the current OEM Danfoss part numbers (121L3070, MTZ160-4VI, 060-200191, 068U2287) to resolve them correctly the first time.

Read more →

Furnace Won't Ignite? How to Diagnose a Draft Inducer Failure

Furnace Won't Ignite? How to Diagnose a Draft Inducer Failure

If a gas furnace won't start or locks out before the burners light, the draft inducer is one of the first components to check. This guide covers how to confirm an inducer failure — symptoms, voltage checks, and confirmed OEM replacement parts for York, Heat Controller, Modine, and more — before you order the wrong part.

Read more →

Pressure Switch Failures: Trane, York & Commercial Units

Pressure Switch Failures: Trane, York & Commercial Units

Pressure switch trips on Trane, York, and commercial units don't all have the same root cause. This guide breaks down brand-specific failure patterns — condensate monitoring, combustion air proving, commercial high-limit, and industrial hydraulic — with OEM part cross-references and a symptom-to-part quick reference table.

Read more →

Armstrong Furnace LED Flash Codes: Diagnose Before You Replace

Armstrong Furnace LED Flash Codes: Diagnose Before You Replace

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.

Read more →