HVAC Companies questions, answered straight

The questions below are the ones homeowners ask right before they hand over money — and the ones the internet answers worst. Most of what comes back is a lead form or a sales page. These are plain answers with nothing to sell.

• What is the $5,000 rule for HVAC?

  Multiply the age of your system by the repair quote. Over $5,000, replace it. Here's how to run it, and the three situations where the rule gets it wrong.

• How much does it cost to replace an HVAC system?

  A full HVAC replacement typically runs $5,000 to $16,000 installed. What sets your number, what a fair quote includes, and how to read three bids against each other.