I have just had the pleasure of replacing a leaking hot water tank serial 9412....so Dec '94. I asked the installer where is the plug for accessing the anode? Eventually we found it, located under the power vent unit which therefore has to be removed in order for an anode to be replaced. I phoned the manufacturer of the replacement unit to complain the anode access on it was also hidden under the vent fan unit. They said they were in no hurry to change the design because they would have to modify their die to stamp out another hole. By the way, you can't simply rotate the fan unit because they run wires down the anode access hole. Bye Bye $1600 !! I would have replaced the anodes, they are $35 and easy to get in the hardware store. I use them to protect the galvanized legs on my dock, they also seem to keep zebra mussels off.