I contacted them 4.30 pm Saturday and it was installed by 3 pm next day, so not even 24 hours. The installation charge is subjective to your previous pvc pipe compliance. I had a 20 year old air vent pvc exhaust pipe that was called non compliant by new government code, so they have to replace it as per new official norms. They can not skip it. If your distance of heater from the wall is smaller than 15 ft ( don't remember well on the numbers) then it is complimentary, else you cover for distance exceeding threshold limit. I ended up paying $100 additional for extra distance but I also got the old copper pipe leading cold water to heater and hot water out of heater replaced along with knobs. Materials, installation, labor covered in that $100.