I had a new Lennox furnace and Air Conditioner installed less than a year ago. I did not know that they used a humidifier and condensate pump and switch off my 20 year old Carrier Furnace. A month later, the humidifier had to be replaced with a new one. Now the condensate pump and switch have worn out, and the contractor is charging me $243.00 to replace the old part with a new one, which should have happened in the first place. I am a retired senior with a fixed income, and this is not helpful to me. No one asked me if they could use old parts. I am a woman, and do not know about furnaces.
Before you pay for a new Furnace, make it clear that you want all new parts, so that the old ones, which are 20 years old by now, will now break down at a later date.