Be aware of 2 Sonoma County HVAC companies
falsely claiming furnaces with cracked heat exchangers.
Get a second opinion.
If you come into contact with a company offering a "$20.00 service call" about your furnace, be aware that the person who shows up is a salesperson who may not evaluate your current equipment correctly.
Honest professional contractors have to charge a reasonable fee for their time to disassemble and investigate a furnace's heat exchanger. Always ask to see the crack in heat exchanger with your own eyes. Don't be scammed. Don't be fooled. Contractors only give free estimates on new equipment.
Service calls always have a fee.
If the fee is a small amount like $20.00, remember customers - these crooked companies will add the true amount of the remaining diagnostic fee to the service call. So always ask questions!