How to sanitize hot water tank?

[Axion]

About two weeks ago the hot water coming out of my taps has had a bit of a smell to it. Nothing major but you can definitely notice a difference from the cold water.



I did change a couple of things before the smell but I'm not sure they would have an impact. First, I am filling my fresh tank instead of using a tap feed. Its getting cold at night here in West Texas and I didn't want to have to worry about freezing a hose up. Second, I switched the hot water heater from propane to electric. I need to conserve my propane for the furnace.



I did a quick test as I have a hot water tank bypass valve in my water system. If I bypass the tank and let the water flow for a minute the smell goes away. As soon as I switch it back and hot water comes out again, the smell is back.



Now, I work in the oilfield and live in my trailer while at work. I work 4 weeks and then go home for 4 weeks. I normally drain my water system completely when I'm gone. Should I be doing something else? And, of course, any ideas on the best way to sanitize the tank?



Thanks in advance for any and all suggestions.

 

[surfbeetle]

The only time that I have had a smell in the system is when I filled with water that had a high sulfur content in it. I think you'll need to drain the tanks, both fresh and the water heater. Then you could use bleach or one of those tank sanitizers at the rv stores that are specific to the drinking water system. Don't use a black tank sanitizer! Then you will need to flush the system out. When you aren't using it, you may need to blow out the system with one of those compressed air adapters so that you don't have any water in it.

 

[Axion]

Compressed air adapters?



I'm pretty new to this whole rv thing. I'm assuming the adapter you refer to attaches where my water hose does. Whats the process? Drain the system, leave the drains open and blow it out?



Sounds like a great idea. I'll have to look for the adapter the next time I'm in town.



Thanks.

 

[Bill Stockard]

The smells coming from your hot water could be from the "good west Texas water" reacting chemically with the anode rod in your water heater. If you leave the water in the tank for a period without using the hot water the smell will get worse.



If it were me, when you leave for your 4 weeks off, I'd switch the lever on your water heater by pass and drain the water heater. When you turn the water heater back on, make sure it has refilled with water. The electric element will burn out in a few seconds if it isn't submerged in water.



Bill

 

[klenger]

Add a couple of Oz of bleech to the hot water tank and fill and then purge. I've had that problem too. I rarely empty my hot water heater because it doesn't get cold enough to freeze here.

 

[ScottLewis]

It's also a good idea to flush out the water heater tank occasionally, especially the aluminum tank ones. I use a fitting on the end of the hose that has a small tube that fits inside the drain hole to dislodge any sand of other particles that may have accumulated inside and flush for several minutes. You'll be surprised at what comes out.



Dan

 

[jjordan1]

Add a cup of bleach to your holding tank & fill about half w\water. Disconnect from the fresh water line. Turn on your water pump & start running water @ the sink,then in the bathroom,then the shower. Stop the water runniing for about 30 minutes. Be sure & run out some hot water . This will allow the bleach water to enter the tank. Then you can drain all line or simply hook back up to city water & run some through the lines to clear the smell of bleach. DONT DRINK FROM YOUR RV FOR A FEW DAYS,USE BOTTLED WATER. dRAIN YOUR HOLDING TANK. tHIS SHOULD SANATIZE YOUR LINES. I DO THIS A COUPLE TIMES PER YEAR. GOOD lUCK

 

[surfbeetle]

Compressed air adapters?



I'm pretty new to this whole rv thing. I'm assuming the adapter you refer to attaches where my water hose does. Whats the process? Drain the system, leave the drains open and blow it out?



Sounds like a great idea. I'll have to look for the adapter the next time I'm in town.



Thanks.

Walmart even has them, it is an adapter that hooks up to the city water connection and then the other end looks like a tire fill valve. Yes, you have the process correct, flush, drain the system and then blow it out with the valves open. Don't use too much air pressure, I can't remember what the air pressure limit is.

 

[Grizzly]

After you have flushed out the hot water tank and the cold water tank with a mixture of bleach and water, flush them again with a mixture of vinegar and water to rid of any bad taste.

 

[The patriot]

Bleach sounds like a good idea, or iodine tabs.

If you've ever cleaned out a coffee pot or tea kettle, use the same thing. I think it active ingredient is hydrochloric acid. It can be had at home depot and is made by Zep. Calcium lime & rust stain remover.



FLUSH LIBERALLY after setting it in there a while.

I dont know how long, but when my kettle gets funked up I let it sit there all day. :-laf

Heating it up should help, but do so carefully!

YMMV

JM. 02

 

[PWitteveen]

Bleach is the recommended chemical for flushing your water system. It is the chlorine in the bleach that sanitizes the system. Is the same thing used in most municipal water systems, only at a lower percentage. If you have the owners manual for your trailer, there should be instructions included on how to sanitize your water system. What danavilla recommended for flushing out the water heater is a good idea. I have read the same procedure in several publications.

 

[BrianJ]

Walmart even has them, it is an adapter that hooks up to the city water connection and then the other end looks like a tire fill valve. Yes, you have the process correct, flush, drain the system and then blow it out with the valves open. Don't use too much air pressure, I can't remember what the air pressure limit is.

Pressure limit is about 45psi for RV lines...

 

[PWitteveen]

The following website includes instructions for sanitizing a water system.

http://www.mckenzierv.com/service/addendums/2001/water_system_tt.pdf

 

[Skydiver]

Speaking from 28 years of employment at a surface water treatment plant.

Get a simple swimming pool chlorine test kit. I had an instructor in water class said he drank water with 50 ppm (PARTS PER MILLION) chlorine while in Korea.

We keep the Free available chlorine residual between 2. 0 and 2. 5 ppm in the towns drinking water. Too much Cl2 (chlorine) in your water will have the same effect as Exlax.

First take your source water from the tap and heat it to 120 degrees F. If you have the odor there you will have the odor in your water heater. A charcoal filter will help with the odor. I do not ever use Charcoal filters because they kill the Cl2 which kills bacteria. It has been found that filters not serviced will actually harbor bacteria.

Axion is your tap water from a city or is it well? If you have city water call them and explain your problem. Be sure to let them know it is hot related. They could flush the mains and I know that helps.

I use 2 oz's bleach in my fresh water tanks to kill bacteria. 1 oz will do. More bleach is not better. Letting it sit 24 hours is better.

I am guessing you have a sulfur odor. When you heat water the molecular action speeds up causing it to release odors. Just like when you put bread in the oven except bread smells good.

28 years experence with water.

 

[icman95]

Grizzly echoes the instructions in my RV's manual. Use bleach in the holding tank(don't know about your setup but I pour it down the hose and then fill the tank) and pump the water through the whole system including the hot water. Let it sit for a while and drain. Repeat with vinegar to neutralize the bleach. Refill and you're good to go. Even it this isn't the fix to the smell, after 4 weeks of not using it, this would be safe to kill any bacteria in the system. Don't forget to pour RV anti freeze down the drain traps in the sinks, tub and toilet when leaving it for home. I made that mistake my first year with it and got VERY LUCKY to not have a big problem. PSI in the RV water system is about 45.



Good luck

 

[B.G. Smith]

Lots of good suggestions here but I doubt that adding chlorine to the system will do anything but cause you more grief. I think Bill Stockard nailed the problem. Also even in home systems, the smell will develop if not used for periods of time. When you drain your water system you need to open the valves at each outlet so the lines can drain. There should be a low point drain in the hot and cold water lines. Also "draining the system" wont drain the hot water tank, you have to remove the drain plug and open the relief valve for it to reaklly drain. There will be those who say that you should not open the relief valve and they may be right but I have been doing it for 30 years with no ill effects. The flushing out idea above is good as there is usually some flaky stuff in the bottom ot the tank.

 

[Axion]

Thanks for all the advice guys. When I bought the rv they sold me some stuff made specifically for sanitizing water systems. But the impression I got was that it was more to clear out any residual taste left from the antifreeze, not to neutralize any odors.



I'm not sure if the water we get out at the rig is from a city supply or a well. They truck it in about every three days or so. I think I'll give the bleach/vinegar thing a try. I'll be going into town tomorrow, so I'll get what I need then.



When I winterized the system back in November I did remove the drain plug on the heater and was amazed at the amount of scale I got out. I'm going to have to find one of those tank cleaning wands and see what happens.



I think what I'll do from now on is drain the system when I go home and do the whole bleach/vinegar thing when I get back. That way I should have a nice clean system for the time I'm at work.



Thanks again for all the help. I really do appreciate it.

 

[icman95]

You know, not to beat a dead horse, but I was thinking that the water may be bad from trucking it in. Perhaps the truck they use isn't sanitized properly on a regular basis and that is making the whole batch bad.



BTW, the stuff the RV dealer sells you to sanitize the system is most likely some relative of bleach anyway. I bought some that is safe to put in the freshwater in the tank to keep it clean for drinking over extended periods of time and the only ingredient was sodium hypochorlite-bleach. Just in a more dilute concetration.



Good luck.

 

[ScottLewis]

The "tank cleaning wand" I use is made up from a hose end connector from the drip irrigation section of the home supply store with a foot long (or so) piece of 1/4" copper tube stuck in it. Not real high tech but it's small enough to allow water to pass by it coming out of the tank and large enough to give adequate pressurized flow in. It also allows you to move it around a bit to sweep the inside of the tank.



Dan