Real HVAC Diagnostic Cases: What We Actually Find When We Open the System
Five real diagnostic findings from service calls across Spring, The Woodlands, Humble, Cypress, and surrounding North Houston communities. These cases illustrate why honest diagnostics matter more than quick part replacements.
Case 1 โ Spring, TX: "The Compressor Is Dead"
The call: Homeowner told by another company the compressor failed. Quote: $7,200 for a new system.
What we found: Failed run capacitor preventing the compressor from starting. Without a capacitor supplying start voltage, the compressor draws locked-rotor amperage and trips the breaker โ appearing dead.
Actual repair: Capacitor replacement โ under $200 including diagnostic fee.
Case 2 โ Humble, TX: "AC Shuts Off Every Afternoon"
The call: System worked in the morning, shut off around 2pm daily, restarted by evening. Homeowner assumed compressor overheating.
What we found: Drain line completely blocked. Drain pan filling by midday, tripping the float switch. System restarted once water evaporated overnight.
Actual repair: Drain line cleared, algaecide treatment applied.
Case 3 โ The Woodlands: "New Thermostat Made Everything Worse"
The call: Homeowner installed a smart thermostat. After installation, the fan ran constantly and wouldn't shut off.
What we found: C-wire used incorrectly โ G (fan) wire used as common wire substitute, causing the fan relay to stay energized continuously.
Actual repair: Thermostat wiring corrected. No parts needed.
Need AC Service in Spring or The Woodlands?
Same-day service available in many cases. Diagnostic fee waived with qualifying repair.
Case 4 โ Kingwood: "Running All Day, House Still Hot"
The call: System ran all day but never reached set point. Multiple contractors had suggested refrigerant addition.
What we found: Evaporator coil completely fouled โ homeowner had run the system without a filter for months. Coil surface insulated by debris, preventing heat exchange entirely.
Actual repair: Professional coil cleaning. System efficiency fully restored.
Case 5 โ Cypress, TX: "New System Still Doesn't Cool"
The call: Homeowner purchased a new system 8 months prior. Back bedrooms still warm, humidity high, bills unchanged.
What we found: System was significantly oversized โ 5-ton unit in a home needing 3.5 tons. Oversized system short-cycled constantly. Two major duct connections left disconnected during installation, dumping conditioned air into a 150ยฐF attic.
Actual repair: Duct connections sealed. Oversizing required longer conversation.
Honest diagnostics before any repair or replacement recommendation: Expo Heating & Cooling Inc checks the full system before recommending anything. Call 832-479-2727 or book online.
