Over a year without emptying the tank? I would think you have a real "science experiment" growing there. We have been living mobile (RVs and boats) for a couple decades; dealing with a fresh water tank is just part of the experience. You aren't going to burn out your pump by running it - that's what they were made to do. Like others, we use bleach to "shock" the tank and lines. I do this before any major trip, but the amount recommended seems to vary... according to the Department of Health for Washington State (
http://www.doh.wa.gov/phepr/handbook/purify.htm), a teaspoon for each 10 gallons (2 teaspoons if the water is very cloudy or cold). That equates to 3 to 6 teaspoons for a 30 gallon tank (there are 192 teaspoons in a quart, by the way).
Mix the bleach in some water before you pour it into the fresh water tank. Almost top the tank off. Go boat for a while to let the bleach slosh around. Pump out all the water... if the noise bothers you, pump while you're running and you probably won't notice it. Or, pump out at the dock while you wash down the exterior of the boat (multi-tasking!
😎 ). Be sure to run water through ALL your lines to make sure they get sanitized, too. When the faucets start to spit air, turn off the pump and fill the tank again with fresh water. Flush it back out again. You will probably still smell some bleach at the faucet. Now, you're ready to fill again for water that you will use. If it still smells bleachy, put a bit of baking soda in the fresh water tank.
This routine is just part of the maintenance a fresh water system needs. We do this at least twice a year in both the boat and the RV. If you are out and about, you are putting water on at different places - it's just a good safety practice to occasionally shock your fresh water system. When filling up water at a marina or RV park, we always use a hose designed for drinking water (white or blue) and run the water before putting it in our tank. Smell it, too. And still put a couple drops of bleach in there.
All this will take you an hour at most, and you can be doing other things at the same time. It's maintenance - just like waxing your boat twice a year, changing oil, putting some Rain-X on the windows, flushing the motor, etc, etc. The best thing for your fresh water system is to use it - put that pump to work!
😉
One more tip: if your water pump is making a lot of noise, it may be due to vibration against the mount. On our boat, I took the pump off where it was mounted, put a bit of non-skid under it, and re-mounted it... it made a substantial reduction in the noise. Sometimes it is as simple as rerouting or securing a water line to reduce the noise.
The fresh water pump in our C-Dory was originally mounted in the bilge... literally where bilge water would get at it. Not surprisingly, it failed after a year or so. I moved the mounting higher and replaced the pump with one supplied by the factory... it died again after about 8 months. I replaced that pump with one made for a "water environment" (Really? A water pump not made for use in a water environment??). These days, we carry a spare when we are out cruising. We can make 30 gallons last a week if we need to conserve, but most of the time, we can go through that amount in a couple days/nights out (as long as we know we can get more). Run the pump - free the water! :mrgreen:
Hope that helps.
Best wishes,
Jim B.
