Plumbing Questions? Ask a Plumber and Get Answers ASAP.
What is the model of your unit? Have you tried unplugging the unit then wait a couple minutes and plug it back in
Ok, did you try starting it back up? does the problem persist? did you post a question similar to this last night?
If the exhaust fan is making a loud noise then that's usually a signal of an imminent failure. It will probably have to be replaced but if the heater is around 10 years old or older it's probably not worth the expense to fix it since the tank could leak at any time
Yes it's safe to just turn it off but you won't have any hot water
If it's not yet 6 years old then it may still be under warranty. Contact Rheem on Monday to discuss your options. If you have the manual call the 800 number in the manual