Update by user Apr 10, 2021 It took 70 days to fix this awful water heater. When it did not work the plumber would talk to A.O.Smith "expert" and he would send out a new part. It did not help. After four times of this, I asked for a new, new water heater. It didn't work either.Finally, a separate company hired by A.O.Smith came out and explained that my 18 year old house had a 2 inch pipe to release the carbon monoxide. CA had changed the regulations. I had to have a 3 inch pipe put in. FINALLY, it worked. Original review posted by user Mar 11, 2021 Horrible water heater product. New water heater had to replace parts 4 times and is still not reliable. Moreover, my plumber spent hours replacing the parts. and a.o. smith only paid him $100.00 per day. I am disgusted User's recommendation: STAY AWAY FROM A.O. SMITH PRODUCTS.