Hot Water

Over the years I’ve used a number of different methods for heating household water. Most people don’t give it much thought -until the water runs cold. Often hot water is heated by a furnace doing double duty. The furnace could be oil, propane or natural gas fired. Heating hot water is fairly efficient when also heating the house. During the warm months it’s less efficient as the furnace is only running to heat water. 

Another common method is the stand alone hot water tank. Usually they are in the 40 – 60 gallon range and are heated by electricity, gas, or oil. There are also tank less water heaters that heat water as you use it. As long as there’s fuel for the heater and water, it will make unlimited hot water. 

One of the things I did many years ago was to install one of the first tank less water heaters in my part of New Hampshire. It ran on propane. When it ran properly it was wonderful. Unfortunately it did not work well during bitterly cold sub zero temperatures. The local propane company had to install an electrically powered heater plate – cutting into its energy efficiency. The unit would also need diaphragms replaced due to freezing on a regular basis. When it finally gave up the ghost the local propane company refused to sell me another one. Instead they put in a regular tank type.

When that one died one summer we were really hard up for money. All I could afford was a cheap 2.5 gallon, 120 volt water heater. It’s the type of heater often installed in a stand alone bathroom where water is only needed for the sink. I was running my whole house on it. It’s just enough water for hand washing, doing dishes, and for very quick Navy style showers. 

It certainly wasn’t enough for a bath. To produce more hot water I built a batch solar hot water heater out of salvaged junk. The solar heater fed into the small electric. Between the solar heater and the small electric we got through the summer. It was cheap to run, but a thrown together batch heater would not survive the cold weather. 

By the time that happened I’d scraped up enough money to buy a 40 gallon electric tank. However I didn’t replace the little tank. It did most of the work on a day by day basis. I rigged up a switch that would turn on the big tank when I wanted a lot of hot water. Now the water heater used 240 volts and switch used 120. The 120 volt switch would trip a 240 volt relay salvaged from a pottery kiln. The odd thing was that the relay made a weird low humming sound the whole time it was engaged. It helped remind me not to leave the switch on all the time so that worked out. 

Right now I’ve got a 40 gallon electric tank that can be preheated from a coil on the back of the woodstove. 

Over the years it’s been a lot of fun and games experimenting with different water heating options. Heating water is a big energy draw so it’s worth looking into ways to do it for less.

-Sixbears