The furnace that we had installed was a Rheem Criterion II Plus. We did not pay for it as we immediately could hear the loud, whining noise that sounded like our local tornado sirens. I asked them to resolve it, they came and told my husband that it sounded defective, replaced a part but that did not help. Their attituded throughout this process was rude and unprofessional. We had them remove the furnace, had a different company install another one and now we have a quiet furnace. Northeast Ohio Heating and Cooling is now suing us for $550 for the use of the furnace for 5 days (for the time that it took them to come back and install a chimney liner, replace a defective part and for me to realize they would not fix it and get a second opinion, which included a weekend). We went one night without a furnace completely because they insisted in taking it out the afternoon the day before the new one was scheduled to have the new one installed. They were also aware that my 85 year old mother in law lives with us because she is the one they convinced we needed a new furnace one day while my husband and I were working. What they are not aware of is that my husband is an attorney.
So, as someone before me said, get an agreement to have it taken out if you are not pleased (especially if you do not know the company with whom you are dealing.)And do not pay too quickly!