Wood Stove is Free Hot Water

The heat is on... The water registered 127 degrees Fahrenheit. The T and P valve should open at 150 degrees F and release the overly hot water. The CDC would like hot water heaters to be at 140 degrees F.

The heat is on… The hot tap  water registers at 127 degrees Fahrenheit. The T and P valve should open at 150 degrees F and release the overly hot water. The CDC would like hot water heaters to be at 140 degrees F, but this will do nicely without scalding us.

Free hot showers for the past three weeks.  The weather outside is cold enough to keep the wood cook stove fired up almost twenty-four seven to heat our home.  With the wood cook stove heating the home, cooking much of our food, and heating our hot water, we have been able to wash dishes, do laundry, and take showers without using propane.

My favorite part of our off grid home is our wood cook stove during the winter.  It is the heart of our home keeping us warm, supplying our cooked food, and heating our domestic hot water throughout the home.  The wood cook stove does not have a reservoir instead it is plumbed into the domestic hot water supplied to each faucet in the house.  When we turn on the hot water faucet at each sink or even the laundry machine, the hot water is derived from the wood cook stove.

No pressure... but if this is not hooked up correctly it could be explosive. The T&P valve is after the pressure gauge that helps monitor the system. The temperature/pressure valve will open if water heats up to 150 degrees and release about 2 gallons of hot water out the drain pipe to a lidded 5 gallon bucket below. In the 2 years we have heated our water with this system our T&P valve has never opened because the water temperature has never risen above 123 degrees.

Like clockwork… The Temperature and Pressure (T & P) valve is directly above the pressure gauge on the left.  The copper pipe running out from the T & P valve leads to a 5 gallon lidded bucket below.  The extra shut-off valves on the right are for a possibly a future solar water heater.

Even though the wood cook stove’s setup is one of my most successful ventures on our off grid home, I cannot explain how much in trepidation I had when hooking it up. I was on a few websites that warned profusely that I was creating a potential bomb that could blow my family up.  The scary thing was that if I did not hook the system up correctly, I could very well have endangered my family and our home.  I kept researching and one person warned me that whatever I do, I must include a T & P valve (Temperature and Pressure Valve) correctly.  I bought one that would open once the temperature of the water rose to 150 degrees Fahrenheit.  Once it reaches that temperature, the valve opens and releases very hot water into a 5 gallon lidded bucket.  I drilled a hole into the bucket’s lid to snugly fit a 1/2″ copper tubing, so the hot water would be safely contained.   Currently, our T & P valve has only opened once without us even realizing it.  When I was cleaning the stove, I discovered the bucket that contains the blow off had about a gallon of water in it.  Some of this I already stated in a previous post “Domestic hot water from a wood cook stove, now that’s a hot idea,” but repetition on safety never hurt any one, frustrate them yes, but never hurt them.

Fired up... The water tank that holds the hot water from the stove is a converted electric water heater (Yellow) to the left. The copper pipe seen next to the stove pipe is the emergency pressure relief system. The orange french press on the stove is my morning coffee.

Fired up… The water tank that holds the hot water from the stove is a converted electric water heater (Yellow) to the left. The copper pipe seen next to the stove pipe is the emergency pressure relief system. The orange french press on the stove is my morning coffee.

Why is a T & P valve important?  Well, without it, the pressure in the water tank or pipes will continue to build pressure from heated water and steam.  If the hot water is not used on a regular basis the tank or pipes could explode under the force of the steam.  Boom!  The other reason is we decided to use PEX piping throughout our house.  PEX does not seem to like temperatures above 175 degrees.  The PEX pipe could be heated to a point that could cause it to fail, weaken, or even melt.  I, therefore, put the T & P valve right before the water system converts to the home’s PEX plumbing line.  The T & P valve keeps the system an open system, not a closed system.  A closed system is very bad when heating water, very bad unless it’s Archimedes steam cannon.

Our hot water system has worked perfectly for the past three years.  I remember testing the newly installed system on August 17, 2013.  We are now successfully running 3 years on the system without a Boom!, but with an “ah” for hot water.



19 thoughts on “Wood Stove is Free Hot Water

  1. Hey Mark

    First, great that you share your works, especially the video!

    I’m planning to make an installation on my own and keep on wondering, how you seal the pipes within the stove?

    Regards from the other side of the pond,


  2. Hey there, i am a sub on your youtube channel . Did you know every video you have the comments are disabled also how many subs you have does not show anymore.
    so no one can respond to you.


    • Dave,
      Thanks for noticing and commenting on my website. Everything you mentioned about my YouTube channel was intentionally done by me. Want to know why? See my post on this website “Firewood and why this YouTube Channel is not Successful
      Thanks for visiting us at Living a Sustainable Dream perhaps you can subscribe here. However, doing so is exactly what YouTube has designed itself to prevent. They can’t make money when you’re on someone else’s platform.


  3. Hi Dave,
    Thank you for such good information for hot water from a wood stove. We had a similar system when I was growing up on our farm. We used the hot water from the wood stove in the winter and in the summer we had a solar outdoor shower. No backup water source so some cool showers in between each season but it worked out great.
    We have been using the Heco 520 wood cook stove for the last year and plan to add hot water similar to your system. Getting information all over the internet and some good articles from Obidiah’s cook stoves (where we got our cookstove from). He suggests using a range boiler tank for its added strength but they are expensive.
    With your system, how many people in your household uses this? We have an extended family and unsure whether just the single coil in the fire box will make enough hot water.
    Thanks for the help, Rob


    • Hi Ron,
      There are 3 of us in the family. I supplement my wood stove hot water with a propane tankless water heater, but during late fall through early spring the wood cook stove does the majority of the work. I get a free shower most mornings during the winter, which cuts down on needing to buy propane. In the summer we are strictly using the propane tankless water heater. We have a 50 gallon electric water heater converted to a range boiler. My system has been in operation for 7 years. Same water tank. I was reading about the range boilers and you can go that way if you want but 7 years going on 8 and no complaints for my system. I am also using a galvanized pipe for the water jacket inside the stove. The stainless developed leaks at the joints within the 1st year. So there is more savings. As far as showers go, 2 quick 10 minute showers in the morning with a hot stove dampered down before bed the evening before, and another shower in the evening. If doing laundry with hot water during the day or night one end of showers night or morning will be used up. Depends on when we run the washing machine. When on vacation, we shower every other day, so that increases the amount of available hot water.


  4. Hi Dave, I am curious, are you using any electricity to move the hot water from the boiler to the shower/washing machine/sinks/etc? Thanks for the post, we are looking to do something similar.


  5. @Michelle,
    Are you asking Dave the subscriber or me the blog creator? My answer is, no. The system is gravity fed and uses natural thermosiphon. The pump is at the cistern and pressurizes the house through a pressure tank. I created a YouTube on this hot water system and my entire off grid water system. Use the Search bar on my website using the term “water”.


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