HVAC IQ Pro

HVAC Tech Blog

Expert guides, diagnostic tools, and industry insights for HVAC professionals. Interactive calculators included.

All Fundamentals (3) Air Distribution (3) Diagnostics (2) Equipment (1) Service & Repair (1) Diagnostics & Theory (1)
Diagnostics 2026-04-21 ๐Ÿ“– 10 min read

TXV Troubleshooting โ€” Stuck Open vs Stuck Closed Symptoms & Diagnosis

The TXV is one of the most misdiagnosed components in HVAC. This guide covers the three failure modes โ€” stuck open, stuck closed, and hunting โ€” with the exact pressure readings and symptoms you'll see in the field.

TXV expansion valve troubleshooting refrigerant cooling
๐Ÿงฎ Interactive Calculator
Diagnostics 2026-04-21 ๐Ÿ“– 12 min read

How to Calculate Superheat and Subcooling โ€” The Complete HVAC Guide

Master the two most critical measurements in HVAC diagnostics. This guide breaks down the math, the meaning, and what the numbers tell you about system health โ€” with a free interactive calculator.

superheat subcooling refrigerant R-410A charging

Monitor Your HVAC Systems in Real-Time

HVAC IQ Pro continuously monitors superheat, delta T, amp draw, and more โ€” catching problems before they become failures.

Try the Interactive Demo โ†’