How to Build a Homemade Water Heater




Introduction: How to Build a Homemade Water Heater

I will show you how to build a cheap and easy water heater to use for camping, hunting cabins, or anywhere that hot water isn't readily available.  I have also include pictures of my finished product.  I travel a lot in my motor home and don't like using LP Gas so I tinkered with some materials and came up with this.  All in-home water heaters use a lot of energy but the one I built uses less than 1200 watts (10 amps).   I wouldn't recommend using this in a house unless you modify the directions as standard houses use water pressure (town water or well).  When I camp out, I take a 1500 watt power inverter and hook to my car battery to heat my water.  I went to Wal-Mart and purchased a shower tent and used cpvc to run into tent and put a valve and a shower head on and it's ready to go. 

Step 1: Step 1

Step 2: Step 2

On this step, you DO NOT have to take the reservoir off of the coffee maker.  You do have to drill (2) 3/4'' holes in the back of the coffee maker to re-route the water lines and you have to take the bottom off the coffee maker to disconnect the old lines and hook up the new lines.  (See Picture in STEP 13)

Step 3: Step 3

Step 4: Step 4

Step 5: Step 5

Step 6: Step 6

Step 7: Step 7

Step 8: Step 8

Step 9: Step 9

Step 10: Step 10

As you can see here,  I have the modified coffee maker sitting on top of the barrel.  I drilled an extra 2 holes in the space that the coffee maker is sitting just in case the hose(s) were to leak from the element and the water will go back into barrel and not onto the ground.  Mine hasn't leaked but it is always better to be safe than sorry.  Don't mind all of the cpvc pipes and valves as I just put together using what parts I had at the time.  I started with using water heater for the shower, then added another line to run to the kitchen sink. 

Step 11: Step 11

This is the picture of my float.  I just used a regular float that goes in the back of the toilet.  The only real problem I've had so far with this set-up is once a month I have to clean the coffee maker element.  I just disconnect the coffee maker from the barrel and poured vinegar down the hose to the element.  Coffee maker must be on to clean as the heat and acidity of vinegar cleans it.  If you don't clean it at least once a month, the element will clog up and you will have to purchase a new coffee maker as it is really hard to get thick layers of lime and calcium out of element.

Step 12: Step 12

This picture here, beside the float, is the water pump (lower right)  I didn't run the pump outlet hose to the top of the lid as explained in the Steps.  I have the float installed on my tank but I manually put water in from the top until I set my cold water tank up.  I use creek or river water to fill my barrel when I travel, but I have a sediment filter that filters my water before putting into barrel to help eliminate the lime and calcium build-up.  I also add 3 drops of bleach for every gallon of water I put in barrel.  Eventually I would like to replace my roof on my motor home so I can collect rain water.

Step 13: Step 13

This picture shows where I drilled the 3/4'' holes for my new hoses to connect to the heating element inside of the coffee maker.  My first try I actually took the coffee maker apart to hook the element up but I had nowhere to put the element so I bought another one and drilled holes and kept assembled.  I also put a small valve on the outlet line going into the barrel.  This is to control the water flow if you have a bigger sized pond/aquarium pump.  I don't recommend using a bigger pump as with this particular valve, I have to clean the lime and calcium build-up every 2 weeks when it isn't completely open.  I don't have a big pump in my set-up but I had the valve laying around so I installed it just as an example.



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    27 Discussions

    I like your idea for my camp, but I found a much easier and less expensive way. Tractor Supply sells a farm animal drinking water trough de-icer that puts out 1000 watts. It comes with a metal guard that places it above the plastic bottom of a barrel and the instructions say it is fine for use in plastic. I will just drop that into my 55 gallon barrel on a timer and use gravity ( it sits up high ) to supply the pressure to my sink. Anyone out there that can poke holes in this idea? Much appreciated

    6 replies

    stock tank deicers do not sufficiently heat water...only enough to prevent freezing. Also, they're thermostatically controlled and only turn on below freezing

    It worked great. I built it this way because I like my showers to start warm and be hot when I'm rinsing off. I use a 1000 watt inverter. I only use it when I travel now, I mainly use a copper pipe solar water heater on my roof.

    That's how we've done it at our deer camp for years. We keep the water barrel about 3 feet above the sink. Never had an issue and it's a much simpler setup.

    That's not a bad idea. How hot does the water get? I will definitely try your idea out. I only use a 22 gallon tank and if heats up the water to 90 or so degrees, I'd be happy lol my model requires a weekly cleaningof the heating element since my water has alot of minerals.

    Mom and dad use one in their horse troughs. Hottest I've seen the water... About 45 degrees. And a couple times it's froze with it running. They have an auto stop. It's made to just keep the water from freezing... Temp drops to fast some times it will still freeze.

    With the materials and time required to be invested in this project and with electricity already onsite, why would you do this instead of just buying a small water heater?

    1 reply



    1 year ago

    hi, i'm planning to make a water heater to produce a little but
    sufficient steam at moderate rate by converting DC battery of
    12v,7.2AH,(15*6.5*9.5)cm to AC of 220v to propel a small boat for the
    project, but the other shows the drawback that we wont be able to
    generate a power, current e.t.c. to heat up the water....... we
    just want our boat to run for a few minutes for a demonstration purpose,
    so please help me to work it out, i'm just having a very time ti figure
    it out what the others are saying, any kind of idea/circuit diagrams
    & components will be highly admired and appreciated .......

    This is interesting and good information to have but for the cost and hassle you can buy a small electric or gas water heater or you can buy an under the counter water heater that has no tank and then again they sell portable propane water heaters that start at just over $100, I've also looked into water heater attachments for wood burners that you can make, again good information to keep in mind for future use when needed


    The idea of a coffee maker is just great.

    Some additional thoughts:

    - insulate the plate with some fireproof insulation

    - did you try using the percolator from the coffee maker instead of the aquarium pump?

    As long as the temperature does not go over 120 °, there will be not too much steam formed.

    Disadvantage: the cold water has to flow by gravity to the plate.

    With a working prototype this is worth a test (use a hose to siphon in order not to make additional holes)

    Great idea here. Not sure if this is helpful but aquarium supply sites sell 300 watt submersible heaters ...we use these to heat storage water for our fish tanks. Some go to 92 F....they willl usually heat 42 galf water in a rubbermade storage pail to temp wiin 2urs....need it faster...add heater....that plus a a submersible pump should work well at least for some applications..the heater brand to loos "ebo". There are also other brands that make inline h

    Add a bit of vinegar to the water. About 1/2 a cup per gallon. It will help the water not go stale and not effect the taste.

    How many watts does the the water pump draw? The coffee maker? This is a very nice idea, but I am curious. You mentioned that you are running the electricity from an inverter, which must be running off your car/truck battery. This means either: A) you have to leave your engine running to keep powering the whole thing; or, B) you have a portable solar charger to keep you batteries going? Which are you using? It seems like heating your shower water like this would burn a lot of gas or diesel, if you're running off of your car batteries. Since you have already invested in a1500 watt inverter, would it be easier to keep your batteries recharged with a couple of portable solar panels and a charge controller? On ebay, for about $30, you can buy a 12 VDC 600 watt immersible water and run it off your batteries all day long, without an inverter and you don't need to worry about the core getting blocked with calcium/lime or sediment. All you need is the solar recharger for your car battery.

    Yea you could do this if u didnt have a lot of cooper around. :)

    Just a thought there are many instructables on bubbler pump. I imagine that this may find a home in this type of application

    Again, NEAT project. However, heat will be lossed at the warmer plate (where carafe sits). A safety concern. As you well know, there is a Thermal cut out switch that is an intrical part of the element/warmer plate which, shuts off electricity to the heater element once the brew cycle is complete. It then, cycles on and off to keep the coffee in the carafe at a certain temperature.The entire project is going to have to rely on this switch. I would be concerned with using a coffee maker to heat up the water in the tank. Good job!

    1 reply

    The cut out switch burned out of my first coffee maker the first time but I had it on for 24 hours a day. It burnt out within 2 months. The second and current coffee maker has been going strong for almost a year now. I leave it on for 8 hours a day on a set timer and I don't leave my motor home without shutting it off. I keep the pond pump running at all times and it pumps a gallon every 4 minutes through the coffee maker. As long as I run pump 24 hours a day (just like in an aquarium), the water temperature in the bottom is around 5 to 10 degrees lower than the top. I inspect coffee maker once a week and clean the lines of lime and calcium once a month. I like it because it only uses 900 watts of power. I still have some kinks to work out but it does the job I built it for. I'm brainstorming an idea to use a heater core for the hot water to run through and use the heat from the water heater to heat my motor home. That way I can be saving even more energy as I could have the potential to have heat and hot water and use 1000 watts of power.