Yes, but to the manufacturer they dont know the difference between someone who cares and someone who's going to hack some shit together. At least with a 'pro' they are in theory a licensed/bonded/insured and someone has validated that they know how to do this work.
FWIW, we have had some hot water issues in the new house and I called a plumbing company out to resolve it. I'm sure I could have done it for 1/2 the price myself but the guy was there for 5 hours, he was nice, professional, fixed what he said was wrong, cleaned up after himself and everything worked great afterwards. I am pleasantly surprised and satisfied. I'll call them back when its time to ditch the fucking heater in the middle of the laundry room for a tankless.
FWIW, we have had some hot water issues in the new house and I called a plumbing company out to resolve it. I'm sure I could have done it for 1/2 the price myself but the guy was there for 5 hours, he was nice, professional, fixed what he said was wrong, cleaned up after himself and everything worked great afterwards. I am pleasantly surprised and satisfied. I'll call them back when its time to ditch the fucking heater in the middle of the laundry room for a tankless.