Hot water heater / boiler as a source of water?

In a thread about food storage the idea of water storage always comes to mind. I was just thinking out loud and realized that my hot water tank holds like 80 gallons of potable water. Has anyone else thought about this?

Certainly! In time of crisis or disaster, your hot water tank could prove to be one of the most useful sources of fresh, potable water. Filled bathtubs could work as well, although the water won't maintain it's "freshness" for nearly as long but will suffice after boiling.

The important thing to realize is that in the event that your tap water becomes undrinkable, it will be important to SHUT OFF water service to your hot water tank lest it becomes infected with the incoming water. To do this, you will NOT be able to use your tap at the sink as hot water is pushed through the line by the pressure of the cold water return. You will need to use the drain tap at the base of the tank to empty it of it's contents. I would still recommend boiling the water before use if it is older than 1 week in the tank as bacteria will begin to form in the water.

During the blackout of 2002 we lost power for almost 3 days and as a result, our local water station lost it's pump pressure which caused a backflush into the system. 4 hours into the blackout we were alerted to boil our water before using. Even then, the water was coming out brown and stinky. So, I shut down the cold water return to the tank and simply drained water from the tap at the base of the tank. This kept us in fresh water throughout the duration of the blackout.

That being said, I wouldn't rely on your hot water tank for very long. 80 gallons sounds like alot of water, but it will go quickly if used for all of your water needs. I filled my bathtubs for non-potable purposes... washing of dishes and utensiles, brushing teeth, cowboy showers etc... I also keep 20 five-gallon carbuoys on hand as a backup. I rotate through those throughout the year to ensure than none is ever older than 6 months old.

On a side note, I saw "This Old House" years ago and they showed what a 5 year old(or so) hot water heater looked like on the inside. Yuck!
LOTS of rust and 'other' stuff after just a few years' use.
They showed some that are better than others, but, said NOT to drink hot water from the tap.
I guess a brita filter or something would help.

Don't forget that your central-heating system contains a good source of potable water too...stop off the radiators at the thermostat and return valves and keep as a supply of last resort

[edit on 6-2-2008 by citizen smith]

if you are considering your water heater as a source of water, you
might open and close the valve on the bottom maybe once a month.
if you do it now you'll probably see brownish minerals blowing out.
sediment and minerals fall to the bottom of every tank. do this once
a month to keep everything clear. another good source of clean
poatble water is the toilet tank.....

On a side note, I saw "This Old House" years ago and they showed what a 5 year old(or so) hot water heater looked like on the inside. Yuck!

must have been a messed up old style water heater , most water heaters if not plastic are glass lined on the inside. If there is rust in your water heater there is rust in you cold water side too.


Several years back i think 2003 an ice storm hit my area and we lost power for 10 days i called it pioneer days at my house. At the time we didnt have city water connected we had a cistern but with no power we had no pump to pump the water to the faucets. Luckily the night before the storm we had just installed a hot tub and i had filled it the night before power went out. No body had been in the tub so i just boiled it on top of the wood burning stove when we needed water. And i f we needed to flush a toilet just simply dump a bucket of water in the toilet and it automatically flushes versus overflowing.

I looked it up;
The program I saw was about 8 years ago, but, it looks as if it could still be true for newer tanks.

Rust in hot water heaters

"Most steel water heater tanks are lined with glass to prevent rust. But the glass lining is never perfect, and the constant temperature fluctuations cause it to expand and contract, causing minute openings. When water eventually penetrates the lining, the tank begins to rust.

At the same time, the heated water causes calcium carbonate to form in the water. It's a type of limestone that you can probably see inside your old teapot. As it forms, the calcium carbonate settles to the bottom of the tank. In gas-fired water heaters, the sediment eventually becomes thick enough at the bottom to reduce the heating efficiency. In electric tanks, sediment collects on the heating element, forming a hard crust that eventually renders the element useless.

To keep your water heater operating correctly, and to extend its life by years, you need to carry out regular maintenance to minimize rust and calcium carbonate.
How to Drain and Clean the Tank...."

Hot water tank, toilet (tank not the bowl, and not if you use chlorinators), the pipes in the walls (open a bottom floor faucet and a top floor one to vent)... lots of water to be had.

Hmm carboys ehh?
I forgot about my 5 gal tanks from my homebrewing days.
There's another 80-100 gallons. I also have my beer tap system that can hold gallons of pressurized drinkables. Hey, wait a minute why not have some emergency stout stock bottled and kegged up? Water is good, but beer is also useful.

I figured the tubs for cleaning so there would be plenty of water there.
Bleeding the pipes is a good idea. My heating registers are useless as they are flushed with an antifreeze solution due to our harsh winters.

The insides of a water heater are steel, when they talk about glass lined they are reffering to fiberglass insulation on the outside to prevent condesation rust from eating the tank from the outside in. Depending on how hard the water in your area is would determine how often you would need to flush your hot water heater.

A cheap solution to treating the water from the tank for critters would be a big pool chlorine tablet. They are sold in individually wrapped packages and last a long time. Just scrape a little off into the water , mix and wait.

If the water is really rusty, just pretend its coffee.

Most Hot water tanks also have anodes in them to attract certains minerals.

I have to learn how to edit my posts. Sorry.

I wouldn't drink out of a stock hot water tank. Some are lined with steel, but many are also just copper inside. Copper is not something you want to ingest; it should be treated like a toxic material, not something you want to have contact with drinking water or food.

For a survival situation though, if the tank was lined with some sort of food-safe material, it'd make sense.

Most interior water pipes are copper...

I'm no plumber but I'm not aware of any modern water heaters that have copper tanks. That would be a rather expensive tank at current copper prices.

>
Yup I'm finding a few and they're pretty pricey. Mostly commercial. Not something your average homeowner is going to have.

[edit on 6-2-2008 by apc]

reply to post by apc


No problem . I remember seeing a cut-away of one, it looked copper anyway. I still wouldn't drink water straight out of anyone's hot water tank, expensive home or not. It'd be useful for non-drinking stuff, but it might not last too long.

Yeah it's not something I would be running to suck on either. In an emergency situation though, Katrina et al, it's not gonna kill you.

If anything it would be great for brushing teeth, flushing toilets, sponge bathing, etc. You want to plan to use a minimum of one gallon of water per day per person for drinking and basic hygiene. Anything extra is a luxury.

If it's not a total apocalyptic scenario and it's in the winter, I however would use the hot water tank as a source of heat. If it's a gas heater that is. It depends on the area... if the water company uses towers there will still be pressure for a little while even if their power backups go down. There will also still be gas pressure. So a hose can be attached to the hot water tank and coiled in a small room, draining into a bathtub or just disposed of. The hose will act as a heating element.

That's what I had planned on doing had the ice storm last year knocked out power here. Fortunately I didn't need to test my idea.

Just for my twopennies worth on this one. May I suggesdt that you invest in a Millbank bag, to filter out any sediment that you get with water from a dirty system or pond, river, stream etc and follow up by using a micro filter. Both these excellent items are available from any good military supplier or even the one I buy my equpiment from, UK based. Silverman's. I use this equipment all the time when I rough it in the moutains and swear by it.

Using both items in conjunction with each other provides good clean drinking water every time.

capt makes a good point, it never ever hurts to have some kind of filtration system on hand.

We dont lose power too often where I live, but when we have storms coming in during the summer, I usually fill up both bath tubs with water. Never had to use the water, but if needed it would be there.

In one of my d/ls I found a method of filtration using pvc tubing filled with layers of sand and charcoal. I may make a few and cap them off for a 'rainy' day.

I'm no plumber either but as for drinking the water out of the hot water tank, I wouldn't. I worked on alot of tanks, new and old and the one thing I allways find in them is Calcium and Lime. You could end up with lime poisoning.

As for staying in your home if theres a major crisis i think the woods would be the safest place.

Interesting Thread.

Could you use the hot water heater to 'boil' the water for you if you turn it up?
I guess natural gas is still needed... but you get my idea.

DocMoreau