HVAC Guides, Calculators &
Troubleshooting Wiki.
Find step-by-step visual solutions for common problems, or use our interactive tools to estimate costs, size equipment, and maximize your energy savings.
HVAC Sizing Calculator
Estimate the required tonnage and BTUs for your home based on square footage and climate.
SEER ROI Calculator
Calculate the payback period and energy savings when upgrading to a higher SEER rating.
Replacement Cost Estimator
Get a ballpark estimate for replacing your AC, furnace, or heat pump.
Thermostat Compatibility Checker
See if your current wiring is compatible with smart thermostats like Nest or Ecobee.
Brand Comparison Tool
Compare major HVAC brands side-by-side to find the right fit for your budget.
Energy Efficiency Advisor
Evaluate your current SEER, AFUE, or HSPF rating against modern standards.
Thermostat Savings Advisor
Calculate how much money you save by adjusting your thermostat when away or sleeping.
Ductwork Sizing Calculator
Determine round and rectangular duct dimensions based on CFM and air velocity.
Ventilation Checker (ASHRAE)
Calculate the required continuous fresh air for your home per ASHRAE 62.2.
BTU to Tonnage Converter
Quickly convert between cooling BTUs, AC Tonnage, and thermal Kilowatts (kW).
VFD Speed & Power Calculator
Calculate frequency and power savings for Variable Frequency Drives using fan affinity laws.
Troubleshooting & How-To Guides
Detailed step-by-step solutions to diagnose and fix the most common residential HVAC problems before you call a pro.
How to Fix an AC Blowing Warm Air
A step-by-step diagnostic guide for when your air conditioner runs but blows hot or ambient air.
What to Do When Your HVAC System Won't Turn On
Follow these 3 crucial steps before calling an HVAC technician to fix a dead system.
How to Change Your HVAC Air Filter
Properly swapping your air filter improves air quality, protects equipment, and lowers utility bills.
How to Fix a Frozen AC Unit
What to do when thick ice builds up on your indoor AC coil or copper lines.
How to Clean Your Outdoor AC Condenser Coils
Keep your AC running efficiently by clearing dirt, leaves, and debris from the outdoor unit.
How to Fix a Furnace That Won't Ignite
Safely troubleshoot a gas furnace that attempts to turn on but fails to produce heat.
How to Clean Air Conditioner Vents
Step-by-step guide for cleaning aircon vents and supply registers to improve airflow and indoor air quality.
What to Do If No Power Is Coming to the Thermostat
Troubleshoot a blank or dead thermostat before calling for HVAC repair in Los Angeles.
How to Fix AC at Home When It Is Not Cooling
Home AC repair checklist: what to check before calling for air conditioning unit repair in Los Angeles.
What system is acting up?
Select your equipment so we can pull the right diagnostic paths.
Frequently Asked Questions
How do I know what size AC unit I need?
We recommend using our HVAC Sizing Calculator as a starting point. It takes into account your square footage and climate zone. For a final decision, a professional Manual J calculation is necessary.
Can I perform my own HVAC repairs?
While our troubleshooting guides help you diagnose common issues and handle simple maintenance (like changing filters or cleaning vents), most electrical and refrigerant repairs legally require a licensed professional.
Are higher SEER ratings always worth the investment?
It depends on your climate and how long you plan to stay in the home. Use our SEER ROI Calculator to see the estimated payback period for upgrading your system.
What should I do if my AC is blowing warm air?
First, check your thermostat settings and air filter. If those are fine, use our Symptom Analyzer below or browse our How-To guides. It could be a refrigerant leak or a faulty capacitor.
