According to the Pennsylvania Home Improvement Law, effective as of July 1 2009, the Licensed Contractor, Christian Heating and Air Conditioning, Inc., shall not perform any home improvement project where the contractor will be paid $500 or more without a written contract signed by the contractor and the owner.  However, it can be completed if it is for an emergency or the homeowner has waived their 3-Day Right of Rescission Act.    
This applies to many other types of Home Improvement work and you can call the toll free number at anytime (1-800-520-6680) to see if your contractor is a licensed professional or look for it on a contractors advertisement, website, contract, vehicles, etc. which should start with the letters PA00 then the contractors number. Christian Heating and Air Conditioning, Inc’s contractor number is PA004411. 
  • Pennslyvania Home Improvement Consumer Protection Act
  • 3 Day Right of Rescission
  • PA Attorney General Site