HVAC Troubleshooting Encyclopedia — LowersHVAC

📚 All (51)❄️ AC & Cooling (10)🔥 Heating & Furnace (8)🔄 Heat Pumps (3)💨 Ductwork & Airflow (4)🌡️ Thermostats & Controls (3)🌬️ Indoor Air Quality (4)⚡ Energy Efficiency & Upgrades (6)🚨 Emergency & Safety (5)🔧 Maintenance & Seasonal (4)🏢 Commercial HVAC (4)

Showing 8 of 8 topics in Heating & Furnace

Furnace Not Producing Heat: Troubleshooting Check thermostat batteries, filter, and gas valve before calling. Pilot light vs electronic ignition—different no-heat scenarios for each system type.

Furnace Short Cycling: Overheating Shutdown Dirty filter, blocked vents, or failing limit switch causing safety shutdown. Why repeated short cycling cracks the heat exchanger—a carbon monoxide risk.

Cracked Heat Exchanger: CO Danger The most dangerous furnace failure—carbon monoxide leaks through cracks. Flame disturbance pattern test and why a cracked heat exchanger means furnace replacement, not repair.

Pilot Light Won't Stay Lit Thermocouple failure, gas valve issue, or draft blowing out the flame. Troubleshooting older standing-pilot furnaces vs modern hot surface igniter systems.

Gas Furnace vs Heat Pump: Cost Comparison Operating cost by climate zone, carbon impact, and dual-fuel systems that switch based on outdoor temperature. The IRA heat pump rebate eligibility explained.

Furnace Filter MERV Rating Guide MERV 8 vs 11 vs 13—higher isn't always better. High-MERV filters restrict airflow and strain the blower unless the ductwork was designed for the pressure drop.

Radiator Cold at Top or Bottom Cold top = trapped air (bleed it). Cold bottom = sludge buildup (needs power flushing). Understanding hydronic heating maintenance.

Boiler Losing Pressure: Leak Diagnosis Pressure relief valve discharge, hidden pipe leaks under floors, or expansion vessel failure—systematically finding pressure loss in hydronic systems.