Funky tasting hot water

Vinegar is an acid that cleans out the hot water tank. It is also used to clean HVAC drip pans and lines out of buildings. The problem with getting it just into the RV hot water tank is the small opening in the vent at the top. Once in it does not back up in to the rest of the water in the RV because of there is a non reversing valve on the intake. That is how the pressure builds up in the tank when it is heating the water, and does not go backwards. The top tank pressure valve,(on the outside), is there to release the pressure if it exceeds the design pressure of the tank. It also spews out the hot water when you open it so BE VERY CAREFUL not to get burnt if the water is heated when servicing the tank. I put the vinegar in through a small flexable tube into the bigger garden hose sized nipple tube I place at the end of the pressure valve. With the hot water faucet open in the kitchen sink and the water pump and or water service connector to land water off, pump in about a quart of white vinegar threw said pipes going into pressure valve at top of tank. Don't have the bottom drain and or hot rod out as they hold the vinegar in. After the quart of vinegar is in fill it the rest of the way with water. Let it sit for a day, and then empty it out the bottom of the tank, and watch the crud come out. Flush with water from the top and or with a hose in the bottom until it runs clear. Stand back when opening or flushing the tank as it will come out in gushes from all the crud. Repeat if necessary until it's clean. This can be done to the entire water system, but Clorox does the job better to the cold water lines, which will clean with the hot water bypassed, and the ice maker line off by the arm being up at the ice water tray. This is a once a year cleaning that takes away the smell caused by metals and mold. The Cloroxed cold water cleaning is usually two cups into the tank vent at top, (watch for splash back as it's also the vent so drip it in),which after a day or two in tank and pumped into the supply lines, ( but not ice maker or hot water tank), draining it out into the black and grey water tanks cleans them, as it does the sewer line to the dump point. Remember Clorox and water becomes salt water, and does bleach and kills vegetation, so dump into an area with care. If smell or taste of vinegar or Clorox is present after any of these procedures you haven't flushed system enough.